pronunciation and speech issues

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Speech Sound Disorders in Children

What are speech sound disorders in children?

It’s normal for young children learning language skills to have some trouble saying words the right way. That’s part of the learning process. Their speech skills develop over time. They master certain sounds and words at each age. By age 8, most children have learned how to master all word sounds.

But some children have speech sound disorders. This means they have trouble saying certain sounds and words past the expected age. This can make it hard to understand what a child is trying to say.  

Speech sound problems include articulation disorder and phonological process disorder.

Articulation disorder is a problem with making certain sounds, such as “sh.”

Phonological process disorder is a pattern of sound mistakes. This includes not pronouncing certain letters.

What causes speech sound disorders in a child?

Often, a speech sound disorder has no known cause. But some speech sound errors may be caused by:

Injury to the brain

Thinking or development disability

Problems with hearing or hearing loss, such as past ear infections

Physical problems that affect speech, such cleft palate or cleft lip

Disorders affecting the nerves involved in speech

Which children are at risk for speech sound disorders?

The cause often is not known, but children at risk for a speech sound disorder include those with:

Developmental disorders such as autism

Genetic disorders such as Down syndrome

Hearing loss

Nervous system disorders such as cerebral palsy

Illnesses such as frequent ear infections

Physical problems such as a cleft lip or palate

Too much thumb-sucking or pacifier use

Low education level of the parent

Lack of support for learning in the home

What are the symptoms of speech sound disorders in a child?

Your child’s symptoms depend on what type of speech sound disorder your child has. He or she may have trouble forming some word sounds correctly past a certain age. This is called articulation disorder. Your child may drop, add, distort, or swap word sounds. Keep in mind that some sound changes may be part of an accent. They are not speech errors. Signs of this problem can include:

Leaving off sounds from words (example: saying “coo” instead of “school”)

Adding sounds to words (example: saying “puhlay” instead of “play”)

Distorting sounds in words (example: saying “thith” instead of “this”)

Swapping sounds in words (example: saying “wadio” instead of “radio”)

If your child often makes certain word speech mistakes, he or she may have phonological process disorder. The mistakes may be common in young children learning speech skills. But when they last past a certain age, it may be a disorder. Signs of this problem are:

Saying only 1 syllable in a word (example: “bay” instead of “baby”)

Simplifying a word by repeating 2 syllables (example: “baba” instead of “bottle”)

Leaving out a consonant sound (example: “at” or “ba” instead of “bat”)

Changing certain consonant sounds (example: “tat” instead of “cat”)

How are speech sound disorders diagnosed in a child?

First, your child’s healthcare provider will check his or her hearing. This is to make sure that your child isn’t simply hearing words and sounds incorrectly.

If your child’s healthcare provider rules out hearing loss, you may want to talk with a speech-language pathologist. This is a speech expert who evaluates and treats children who are having problems with speech-language and communication.                       

By watching and listening to your child speak, a speech-language pathologist can determine whether your child has a speech sound disorder. The pathologist will evaluate your child’s speech and language skills. He or she will keep in mind accents and dialect. He or she can also find out if a physical problem in the mouth is affecting your child’s ability to speak. Finding the problem and getting help early are important to treat speech sound disorders.

How are speech sound disorders treated in a child?

The speech-language pathologist can put together a therapy plan to help your child with his or her disorder. These healthcare providers work with children to help them:

Notice and fix sounds that they are making wrong

Learn how to correctly form their problem sound

Practice saying certain words and making certain sounds

The pathologist can also give you activities and strategies to help your child practice at home. If your child has a physical problem in the mouth, the pathologist can refer your child to an ear, nose, throat healthcare provider or orthodontist if needed.

Spotting a speech sound disorder early can help your child overcome any speech problems. He or she can learn how to speak well and comfortably.

How can I help my child live with a speech sound disorder?

You can do things to take care of your child with a speech sound disorder:

Keep all appointments with your child’s healthcare provider.

Talk with your healthcare provider about other providers who will be involved in your child’s care. Your child may get care from a team that may include experts such as speech-language pathologists and counselors. Your child’s care team will depend on your child’s needs and the severity of the speech sound disorder.

Tell others of your child’s disorder. Work with your child’s healthcare provider and schools to develop a treatment plan.

Reach out for support from local community services. Being in touch with other parents who have a child with a speech sound disorder may be helpful.

When should I call my child’s healthcare provider?

Call your child’s healthcare provider if your child has:

Symptoms that don’t get better, or get worse

New symptoms

Key points about speech sound disorders in children

A speech sound disorder means a child has trouble saying certain sounds and words past the expected age.

A child with an articulation disorder has problems making certain sounds the right way.

A child with phonological process disorder regularly makes certain word speech mistakes.

The cause of this problem is often unknown.

A speech-language pathologist can help diagnose and treat a speech sound disorder.

Tips to help you get the most from a visit to your child’s healthcare provider:

Know the reason for the visit and what you want to happen.

Before your visit, write down questions you want answered.

At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

Ask if your child’s condition can be treated in other ways.

Know why a test or procedure is recommended and what the results could mean.

Know what to expect if your child does not take the medicine or have the test or procedure.

If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.

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Mispronunciation: why you should stop correcting people’s mistakes

Professor of Phonetics, University of Reading

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Jane Setter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

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A recent survey of 2,000 adults in the UK identified the top ten “mispronunciations” people find annoying. Thankfully the majority (65%) of annoyed people do not feel comfortable correcting a speaker in public.

But leaving aside the fact that 2,000 is hardly a representative sample of the UK, with its population of over 66 million , this survey raises longstanding linguistic questions: why do people pronounce words differently, why does pronunciation change, and why does so-called mispronunciation upset some people to the point of making it possible (and interesting) to compile a top ten list?

I’m a phonetician – an expert in the way people make speech sounds and pronounce language. I’ve also written about what we can learn about a person from the way they speak .

A universal truth about language is that it is subject to constant change – and pronunciation is just as likely to change over time as aspects like grammar or vocabulary.

How language changes

One criticism of speakers who pronounce nuclear (“NU-cle-ar”) as “nucular” is that it does not match the spelling. In fact, English is known for having some very irregular spelling-to-sound correspondences, so that argument does not always hold up. The most extreme cases are probably family and place names: the surname Featherstonehaugh can be pronounced to sound like “Fanshaw”, for example, while Torpenhow in Cumbria is pronounced “Trepenna”.

How did we get to those pronunciations? Through a process of gradual, historical language change. These changes could be the result of social interaction (“other people say it like this”), mishearings, spelling pronunciations, phonetic processes or the influence of other languages, among other things. Certainly, language change is inevitable, which is handy because it keeps us linguists in business and generates a lot of copy for newspapers and the like.

Let’s have a look at some of the pronunciations people objected to in that survey.

“Espresso” is pronounced “expresso” by many people, even though there is no “x” in the spelling. This pronunciation probably arose by analogy with the word “express”. The two are actually cognate words with similar origins, both meaning “press out” or “obtain by squeezing”.

If you hear someone ask for an espresso, it’s easy to see how you might mishear this to be nearer to a word you already know, and therefore adopt that pronunciation. Importantly, you are unlikely to misunderstand what the speaker has asked for.

We don’t have a similar issue with the pronunciation of “cappuccino” or “macchiato” because we simply don’t have anything similar to those words in English. Incidentally, I’m reliably informed that the French word for “espresso” is “expresso”. Vive la différence.

The pronunciation of “probably” as “probly” likely arises from a process called weak syllable elision or deletion. The weak second syllable in “probably” is often deleted in speech. A similar phenomenon happens in “especially”, pronounced “specially” – the first syllable is weak and is deleted. In English, the most important syllables for listener comprehension are stressed. That’s why young children acquiring language say “tatoes” for “potatoes”, or “jamas” for “pyjamas”.

In rapid adult speech, it is very likely that these weaker syllables will be deleted. As George Bailey, a sociolinguist at the University of York, notes , it is interesting that “probably” and “especially” are singled out when we do this with many words. He gives the examples “memory” (pronounced “MEM-ry”) and “library” (pronounced “LI-bry”), which did not make the list.

I have, however, noticed a recent change in the way some words which have historically had weak syllable elision are pronounced. For example, “irreparable” seems to be changing from four syllables with a main stress on the second (“ir-REP-ra-ble”) to five syllables with the main stress on the third (“ir-re-PAR-a-ble”), with the stressed syllable sounding like “pear”. I’m not entirely sure what is going on here, but it could be by analogy with the word “repair”, or with “comparable”, which seems to be shifting from “COM-pra-ble” to “com-PAR-a-ble”.

The last word I’ll draw out for examination is “Arctic”, pronounced “Artick”. It is possible that the first “c” might not be heard in rapid speech, even if a speaker is articulating it. This is because it is produced further back in the oral cavity than the following “t”, and so its release can be masked.

Historically, as Graham Pointon, formerly the BBC’s pronunciation adviser, has noted , the Chambers Etymological Dictionary lists the earliest English version as “Artic”. The “c” could have been reinserted during the Renaissance period, when scholars sought to reform English spelling to reflect classical languages such as Latin and Greek.

Unfortunately they also reformed the spelling of words which had entered the language via other routes. This gave us such fun spellings as “debt” for what had been written “dette” in Middle English and came from Old French “dete” (and of course we don’t pronounce the “b” in “debt”).

Another route for language change is the influence of other speakers. I’m half-expecting people to start pronouncing “microwave” quite differently following this viral clip of Nigella Lawson . I’ve already had discussions with people who say they have adopted it “just for fun”. How long before it goes mainstream?

Pronunciation and prejudice

So what does all this say about the 35% of people who feel compelled to correct so-called mispronunciations in public? Nothing good, in my opinion. It seems to be a pedantic display of perceived superiority which can only result in the person with the “unacceptable” pronunciation looking stupid.

The way people speak and pronounce words is very much dependent on their language background and experience. By correcting a pronunciation that you have actually understood but somehow object to, you could be inadvertently – or even purposefully – pointing out perceived deficiencies arising from differences in social class, culture, race, gender, and so on.

Correcting pronunciation can actually be an act of linguistic prejudice. This is different from correcting a language learner in a pronunciation classroom or asking someone to repeat something you have not understood, for example. Taking someone politely aside is less threatening, but you should still consider your motivations for doing so.

It might not always be the case that the corrector’s motivations are self-centred. My father always corrected me (in private) because he believed that having a “non-standard” accent – particularly one which is perceived as ugly by some – would negatively affect my career prospects. Sadly, at the time (this was the 1980s), I think my father was right.

Issues of linguistic prejudice linked to race and class are still alive and well, as was recently brought into sharp focus in an article on the American television news journalist Deion Broxton. The good news is that linguists in the UK are actively working on research and resources to help combat accent prejudice.

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Speaking clearly: Help for people with speech and language disorders

• Speech-Language

Speaking and language abilities vary from person to person. Some people can quickly articulate exactly what they are thinking or feeling, while others struggle being understood or finding the right words.

These struggles could be due to a speech or language disorder if communication struggles cause ongoing communication challenges and frustrations. Speech and language disorders are common.

It's estimated that 5% to 10% of people in the U.S. have a communication disorder. By the first grade, about 5% of U.S. children have a noticeable speech disorder. About 3 million U.S. adults struggle with stuttering and about 1 million U.S. adults have aphasia. These conditions make reading, speaking, writing and comprehending difficult.

People with speech and language disorders can find hope in rehabilitation. Speech-language pathologists can evaluate and treat these disorders. This can lead to a happier, healthier and more expressive life.

Types of speech and language disorders

Speech and language disorders come in many forms, each with its own characteristics:.

• Aphasia People with aphasia have difficulty with reading, writing, speaking or understanding information they've heard. The intelligence of a person with aphasia is not affected.
• Dysarthria People with dysarthria demonstrate slurred or imprecise speech patterns that can affect the understanding of speech.
• Apraxia A person with this disorder has difficulty coordinating lip and tongue movements to produce understandable speech.
• Dysphagia This condition refers to swallowing difficulties, including food sticking in the throat, coughing or choking while eating or drinking, and other difficulties.
• Stuttering This speech disorder involves frequent and significant problems with normal fluency and flow of speech. People who stutter know what they want to say but have difficulty saying it.
• Articulation disorder People with this disorder have trouble learning how to make specific sounds. They may substitute sounds, such as saying "fum" instead of "thumb".
• Phonological disorder Phonological processes are patterns of errors children use to simplify language as they learn to speak. A phonological disorder may be present if these errors persist beyond the age when most other children stop using them. An example is saying "duh" instead of "duck."
• Voice Voice disorders include vocal cord paralysis, vocal abuse and vocal nodules, which could result in vocal hoarseness, changes in vocal volume and vocal fatigue.
• Cognitive communication impairment People with cognitive communication impairment have difficulty with concentration, memory, problem-solving, and completion of tasks for daily and medical needs.

Speech and language disorders are more common in children. It can take time to develop the ability to speak and communicate clearly. Some children struggle with finding the right word or getting their jaws, lips or tongues in the correct positions to make the right sounds.

In adults, speech and language disorders often are the result of a medical condition or injury. The most common of these conditions or injuries are a stroke, brain tumor, brain injury, cancer, Parkinson's disease, multiple sclerosis, Lou Gehrig's disease or other underlying health complications.

Treatment options

Speech and language disorders can be concerning, but speech-language pathologists can work with patients to evaluate and treat these conditions. Each treatment plan is specifically tailored to the patient.

Treatment plans can address difficulties with:

• Speech sounds, fluency or voice
• Understanding language
• Sharing thoughts, ideas and feelings
• Organizing thoughts, paying attention, remembering, planning or problem-solving
• Feeding and swallowing
• Vocabulary or improper grammar use

Treatment typically includes training to compensate for deficiencies; patient and family education; at-home exercises; or neurological rehabilitation to address impairments due to medical conditions, illnesses or injury.

Treatment options are extensive and not limited by age. Children and adults can experience the benefits of treatment.

If you or a loved one are struggling with speech and language issues, you are not alone. Millions of people experience similar daily challenges. Better yet, help is available.

Monica Marzinske is a speech-language pathologist  in New Prague , Minnesota.

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Speech Pronunciation for Kids: Tips, Tools, and Resources

December 16, 2022 

For various reasons, children may struggle to pronounce words correctly and may eventually develop a speech disorder. Signs of a speech disorder may include stuttering, repetition, blocks (difficulty forming words), and prolongation (drawing out certain sounds). To reduce a child’s risk of developing a speech impediment, parents can engage their children in a variety of activities designed to be fun and educational. Some children, however, will require the help of an experienced speech-language pathologist.

To learn about tips and resources on speech pronunciation for kids, check out the infographic below, created by Maryville University’s online Master of Science in Speech-Language Pathology program .

American Speech-Language-Hearing Association, Childhood Apraxia of Speech

American Speech-Language-Hearing Association, Child Speech and Language

American Speech-Language-Hearing Association, Dysarthria

American Speech-Language-Hearing Association, Speech Sound Disorders-Articulation and Phonology

Hackensack Meridian Health, “Signs Your Child Should See a Speech Therapist”

Medical News Today, “What Are Speech Disorders?”

Parent Circle, “How to Teach Pronunciation to Your Child. Here Are 11 Pointers for Parents”

Speech Buddy, “Our 6 Favorite Apps for Kids with Speech Impediments”

What Parents Need to Know About Speech Pronunciation for Kids

Learning about the signs and causes of speech disorders will empower parents to take steps early to help their children improve pronunciation.

Types of Speech Disorders

Functional speech sound disorders are speech errors of unknown cause and include articulation disorders and phonological disorders. Articulation disorders focus on errors in pronunciation of individual speech sounds; errors may include distortions and substitutions. Phonological disorders focus on predictable, rule-based errors that affect more than one sound; errors may include fronting (when sounds that should be made in the back of the mouth are moved to the front), stopping, and final consonant deletion.

Organic speech sound disorders, which include childhood apraxia of speech (CAS) and dysarthria, result from underlying causes such as motor, neurological, structural, sensory, or perceptual issues. CAS occurs when messages from the brain fail to travel to the mouth, making it difficult for the child to move their lips or tongue correctly. Dysarthria occurs when brain damage causes weak muscles; it may occur with apraxia.

Signs and Symptoms of Speech Disorders

Symptoms of functional speech sound disorders include omissions/deletions (excluding certain sounds), substitutions (substituting one or more sounds), additions (adding one or more extra sounds to a word), distortions (altering or changing sounds), and syllable-level errors (deleting weak syllables).

Children with CAS may place stress on the wrong syllable or word, distort or change sounds, struggle to say longer words, and pronounce the same word in different ways. Children may have dysarthria if they talk too fast or too slowly, slur or mumble their words, speak softly, produce robotic or choppy sounds, or struggle to move their tongue, lips, and jaw.

Activities Parents Can Use to Teach Pronunciation

Parents can introduce fun activities according to the child’s age and speaking skills to help address various speech impediments.

Speech Pronunciation Exercises and Learning Activities for Kids

When teaching kids pronunciation, parents should focus on sounds (vowels, diphthongs, and consonants), stress (where the accent is placed on syllables), and intonation (raising and lowering of the voice). Secondary aspects of speech parents can teach include volume, pitch, pause, and pace.

Parents can teach beginner-level pronunciation using speech pronunciation exercises and activities. For instance, popular songs such as the “Happy Birthday” song help kids naturally learn pronunciation. Nursery rhymes, accompanied with music, can teach kids proper timing, stress, and intonation.

Repetition can also help, as asking a child to repeat a word will help create a permanent memory. Parents can use the minimal pairs exercise, where replacing consonants or vowels in words can help kids recognize differences in words. They can also use easy and relevant vocabulary, since teaching words according to context can help kids understand meaning and proper use.

Intermediate-level activities may involve recording and replaying the child’s speech to help them identify mistakes and make improvements, showing a child how their mouth moves in a mirror to teach proper articulation and the nature of various sounds, and teaching kids how to identify specific sounds from word pairs and groups (auditory discrimination).

Children learning advanced speech pronunciation can engage in chants, which can help teens or preteens understand how intonations differ in statements, exclamations, and questions. They can also practice connected speech, which shows them when to connect words (such as in “black-coffee,” rather than pronouncing two separate /k/ sounds). They can also try repeating tongue twisters.

Helpful Tools and Professional Speech Therapy

Parents also have access to online tools and apps created by professional speech and language pathologists to help children learn speech in a fun and relaxed environment.

Speech Pronunciation Games for Kids

The Articulation Games app was created for children by a certified speech-language pathologist to practice the pronunciation of over 40 English phonemes (single sounds that are part of the phonetic system). The app includes thousands of flashcards, professional audio recordings, and matching games.

The Fun with R app was created to help kids learn to produce the “r” sound and includes over 2,000 audio-recorded words that contain the “r” sound and “r” blends.

The Articulation Station app was created for children by a certified speech-language pathologist to help kids learn to speak and pronounce words clearly. It includes high-quality images and activities covering various word, sentence, and story levels.

Children who need help learning nouns, verbs, prepositions, and adjectives should try Splingo’s Language Universe. The app includes thousands of different word and sentence possibilities and a range of language development options.

ArtikPix is an entertaining articulation app with matching activities created for children with speech impediments. Up to 24 card decks (with 40 cards each) can be selected by sound group, combined, or practiced with flashcard and matching activities.

When to Seek Professional Speech Therapy

Children may need professional speech therapy if they don’t meet speech development goals for their age. For example, children ages 12 to 15 months who can make only a few sounds, haven’t spoken their first words, or are unable to wave, point, or make other gestures may have fallen behind most of their peers.

Children ages 18-24 months should be able to use two-word combinations regularly, pronounce endings of words, and communicate their desires verbally rather than by pointing or grunting.

Concerning signs that children ages 2-4 years may exhibit include struggling to put two- and three-word combinations together, producing mostly unintelligible sounds, and having a vocabulary of fewer than 50 words.

Children ages 4-5 years may need professional speech therapy if they repeat the first sounds of words, are unable to follow simple classroom directions, or constantly repeat sounds or words.

Meeting Speech Pronunciation Goals for Kids

Parents should consider seeking professional help if at-home activities don’t produce adequate results. A professional speech-language pathologist can help children improve pronunciation and reach an age-appropriate level.

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Speech Sound Disorders in Children: An Articulatory Phonology Perspective

Aravind kumar namasivayam.

1 Oral Dynamics Laboratory, Department of Speech-Language Pathology, University of Toronto, Toronto, ON, Canada

2 Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada

Deirdre Coleman

3 Independent Researcher, Surrey, BC, Canada

Aisling O’Dwyer

4 St. James’s Hospital, Dublin, Ireland

Pascal van Lieshout

5 Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada

Speech Sound Disorders (SSDs) is a generic term used to describe a range of difficulties producing speech sounds in children ( McLeod and Baker, 2017 ). The foundations of clinical assessment, classification and intervention for children with SSD have been heavily influenced by psycholinguistic theory and procedures, which largely posit a firm boundary between phonological processes and phonetics/articulation ( Shriberg, 2010 ). Thus, in many current SSD classification systems the complex relationships between the etiology (distal), processing deficits (proximal) and the behavioral levels (speech symptoms) is under-specified ( Terband et al., 2019a ). It is critical to understand the complex interactions between these levels as they have implications for differential diagnosis and treatment planning ( Terband et al., 2019a ). There have been some theoretical attempts made towards understanding these interactions (e.g., McAllister Byun and Tessier, 2016 ) and characterizing speech patterns in children either solely as the product of speech motor performance limitations or purely as a consequence of phonological/grammatical competence has been challenged ( Inkelas and Rose, 2007 ; McAllister Byun, 2012 ). In the present paper, we intend to reconcile the phonetic-phonology dichotomy and discuss the interconnectedness between these levels and the nature of SSDs using an alternative perspective based on the notion of an articulatory “gesture” within the broader concepts of the Articulatory Phonology model (AP; Browman and Goldstein, 1992 ). The articulatory “gesture” serves as a unit of phonological contrast and characterization of the resulting articulatory movements ( Browman and Goldstein, 1992 ; van Lieshout and Goldstein, 2008 ). We present evidence supporting the notion of articulatory gestures at the level of speech production and as reflected in control processes in the brain and discuss how an articulatory “gesture”-based approach can account for articulatory behaviors in typical and disordered speech production ( van Lieshout, 2004 ; Pouplier and van Lieshout, 2016 ). Specifically, we discuss how the AP model can provide an explanatory framework for understanding SSDs in children. Although other theories may be able to provide alternate explanations for some of the issues we will discuss, the AP framework in our view generates a unique scope that covers linguistic (phonology) and motor processes in a unified manner.

Introduction

In clinical speech-language pathology (S-LP), the distinction between articulation and phonology and whether a speech sound error 1 arises from motor-based articulation issues or language/grammar based phonological issues has been debated for decades (see Shriberg, 2010 ; Dodd, 2014 ; Terband et al., 2019a for a comprehensive overview on this topic). The theory-neutral term Speech Sound Disorders (SSDs) is currently used as a compromise to bypass the constraints associated with the articulation versus phonological disorder dichotomy ( Shriberg, 2010 ). The present definition describes SSD as a range of difficulties producing speech sounds in children that can be due to a variety of limitations related to perceptual, speech motor, or linguistic processes (or a combination) of known (e.g., Down syndrome, cleft lip and palate) and unknown origin ( Shriberg et al., 2010 ; McLeod and Baker, 2017 ).

The history of causality research for childhood SSDs encompasses several theoretically motivated epochs ( Shriberg, 2010 ). While the first epoch (1920s-1950s) was driven by psychosocial and structuralist views aimed at uncovering distal causes, the second epoch (1960s to 1980s) was driven by psycholinguistic and sociolinguistic approaches and focused on proximal causes. The more recent third and fourth epochs reflect the utilization of advances in neurolinguistics (1990s) and human genome sequencing (post-genomic era; 2000s) and these approaches address both distal and proximal causes ( Shriberg, 2010 ). With these advances, several different systems for the classification of SSD subtypes in children have been proposed based on their distal or proximal cause (e.g., see Waring and Knight, 2013 ). Some of the major SSD classification systems include the Speech Disorders Classification System ( Shriberg et al., 2010 ), the Model of Differential Diagnosis ( Dodd, 2014 ) and the Stackhouse and Wells (1997) Psycholinguistic Framework. However, a critical problem in these classification systems as noted by Terband et al. (2019a) is that the relationships between the different levels of causation are underspecified. For example, the links between the etiology (distal; e.g., genetics), processing deficits (proximal; e.g., psycholinguistic factors), and the behavioral levels (speech symptoms) are not clearly elucidated. In other words, even though the term SSD is theory-neutral, the poorly specified links between the output level (behavioral) speech symptoms and higher-level motor/language/lexical/grammar processes limits efficient differential diagnosis, customizing intervention and optimizing outcomes (see Terband et al., 2019a for a more detailed review on these issues). Thus, there is a critical need to understand the complex interactions between the different levels that ultimately cause the observable speech symptoms ( McAllister Byun and Tessier, 2016 ; Terband et al., 2019a ).

There have been several theoretical attempts at integrating phonetics and phonology in clinical S-LP. In this context, the characterization of speech patterns in children either solely as the product of performance limitations (i.e., challenges in meeting phonetic requirements arising from motor and anatomical differences) or purely as a consequence of phonological/grammatical competence has been challenged ( Inkelas and Rose, 2007 ; Bernhardt et al., 2010 ; McAllister Byun, 2012 ). McAllister Byun (2011 , 2012) and McAllister Byun and Tessier (2016) suggest a “phonetically grounded phonology” approach where individual-specific production experience and speech-motor development is integrated into the construction of children’s phonological/grammatical representations. The authors discuss this approach using several examples related to the neutralization of speech sounds in word onset (with primary stress) positions. They argue that positional velar fronting in these positions (where coronals sounds are substituted for velar) in children is said to result from a combination of jaw-dominated undifferentiated tongue gesture (e.g., Gibbon and Wood, 2002 ; see Section “Speech Delay” for details on velar fronting and undifferentiated tongue gestures) and the child’s subtle articulatory efforts (increased linguo-palatal contact into the coronal region) to replicate positional stress ( Inkelas and Rose, 2007 ; McAllister Byun, 2012 ). McAllister Byun (2012) demonstrated that by encoding this difficulty with a discrete tongue movement as a violable “MOVE-AS-UNIT” constraint, positional velar fronting could be formally discussed within the Harmonic Grammar framework ( Legendre et al., 1990 ). In such a framework the constraint inventory is dynamic and new constraints could be added on the basis of phonetic/speech motor requirements or removed over the course of neuro-motor maturation. In the case of positional velar fronting, the phonetically grounded “MOVE-AS-UNIT” constraint is eliminated from the grammar as the tongue-jaw complex matures ( McAllister Byun, 2012 ; McAllister Byun and Tessier, 2016 ).

In the present paper, we intend to reconcile the phonetic-phonology dichotomy and discuss the interconnectedness between these levels and the nature of SSDs using an alternative perspective. This alternative perspective is based on the notion of an articulatory “gesture” that serves as a unit of phonological contrast and characterization of the resulting articulatory movements ( Browman and Goldstein, 1992 ; van Lieshout and Goldstein, 2008 ). We discuss articulatory gestures within the broader concepts of the Articulatory Phonology model (AP; Browman and Goldstein, 1992 ). We present evidence supporting the notion of articulatory gestures at the level of speech perception, speech production and as reflected in control processes in the brain and discuss how an articulatory “gesture”-based approach can account for articulatory behaviors in typical and disordered speech production ( van Lieshout, 2004 ; van Lieshout et al., 2007 ; D’Ausilio et al., 2009 ; Pouplier and van Lieshout, 2016 ; Chartier et al., 2018 ). Although, other theoretical approaches (e.g., Inkelas and Rose, 2007 ; McAllister Byun, 2012 ; McAllister Byun and Tessier, 2016 ) are able to provide alternate explanations for some of the issues we will discuss, the AP framework in our view generates a unique scope that covers linguistic (phonology) and motor processes in a unified and transparent manner to generate empirically testable hypotheses. There are other speech production models, but as argued in a recent paper, the majority of those are more similar to the Task Dynamics (TD) framework ( Saltzman and Munhall, 1989 ) in that they address specific issues related to the motor implementation stages (with or without feedback) and not so much include a principled account of phonological principles, such as formulated in AP ( Parrell et al., 2019 ).

Articulatory Phonology

This section on Articulatory Phonology (AP; Browman and Goldstein, 1992 ) lays the foundation for understanding speech sound errors in children diagnosed with SSDs from this specific perspective. The origins of the AP model date back to the late 1970s, when researchers at the Haskins laboratories developed a unique and alternative perspective on the nature of action and representation called the Task Dynamics model (TD; Saltzman and Munhall, 1989 ). This model was inspired by concepts of self-organization related to functional synergies as derived from the Dynamical Systems Theory (DST; Kelso, 1995 ).

DST in general describes behavior as the emergent product of a “ self organizing, multi-component system that evolves over time ” ( Perone and Simmering, 2017 , p. 44). Various aspects of DST have been studied and applied in a diverse range of disciplines such as meteorology (e.g., Zeng et al., 1993 ), oceanography (e.g., Dijkstra, 2005 ), economics (e.g., Fuchs and Collier, 2007 ), and medical sciences (e.g., Qu et al., 2014 ). Recently, there has also been an uptake of DST informed research related to different areas in cognitive and speech-language sciences, including language acquisition and change ( Cooper, 1999 ); language processing ( Elman, 1995 ); development of cognition and action ( Thelen and Smith, 1994 ; Spencer et al., 2011 ; Wallot and van Orden, 2011 ); language development ( van Geert, 1995 , 2008 ); 2nd language learning and development ( de Bot et al., 2007 ; de Bot, 2008 ); speech production (see van Lieshout, 2004 for a review; van Lieshout and Neufeld, 2014 ; van Lieshout, 2017 ); variability in speech production ( van Lieshout and Namasivayam, 2010 ; Jackson et al., 2016 ); connection between motor and language development ( Parladé and Iverson, 2011 ); connection between cognitive aspects of phonology and articulatory movements ( Tilsen, 2009 ); and visual word recognition ( Rueckle, 2002 ); and visuospatial cognitive development ( Perone and Simmering, 2017 ).

The role of DST in speech and language sciences, in particular with respect to speech disorders, is still somewhat underdeveloped, mainly because of the challenges related to applying specific DST analyses to the relatively short data series that can be collected in speech research ( van Lieshout, 2004 ). However, we chose to focus on the AP framework, as it directly addresses issues related to phonology and articulation using DST principles related to relative stable patterns of behaviors (attractor states), that emerge when multiple components (neural, muscular, biomechanical) underlying these behaviors interact through time in a given context (self-organization) as shown in the time varying nature of the relationship between coupled structures (synergies) that express those behaviors ( Saltzman and Munhall, 1989 ; Browman and Goldstein, 1992 ). Some examples of studies using this AP/DST approach can be found in papers on child-specific neutralizations in primary stress word positions ( McAllister Byun, 2011 ), articulation issues related to /r/ production ( van Lieshout et al., 2008 ), apraxia of speech ( van Lieshout et al., 2007 ), studies on motor speech processes involved in stuttering ( Saltzman, 1991 ; van Lieshout et al., 2004 ; Jackson et al., 2016 ), phonological development ( Rvachew and Bernhardt, 2010 ), SSDs ( Gildersleeve-Neumann and Goldstein, 2015 ), and in children with repaired cleft-lip histories ( van Lieshout et al., 2002 ). In the next few sections we will review the concept of synergies and the development of speech motor synergies, which are directly related to DST principles of self-organization and coupling, followed by how the AP model uses these concepts to discuss linguistic/phonological contrast.

Speech Motor Synergies

The concept of speech motor synergy was derived from DST principles based on the notion that complex systems contain multiple (sub)components that are (functionally and/or physically) coupled ( Kelso, 1995 ). This means that these (sub)components interact and function as a coordinated unit where patterns emerge and dissolve spontaneously based on self-organization, that is, without the need of a pre-specified motor plan ( Turvey, 1990 ). These patterns are generated due to internal and external influences relating to inter-relationships between the (sub)components themselves, and the constraints and opportunities for action provided in the environment ( Smith and Thelen, 2003 ). Constraints or specific boundary conditions that influence pattern emergence may relate to physical, physiological, and functional/task constraints (e.g., Diedrich and Warren, 1995 ; Kelso, 1995 ; van Lieshout and Namasivayam, 2010 ). Such principles of pattern formation and coupling have already been demonstrated in physical (e.g., Gunzig et al., 2000 ) and biological systems (e.g., Haken, 1985 ), including neural network dynamics (e.g., Cessac and Samuelides, 2007 ). Haken et al. (1985) , Kelso et al. (1985) , and Turvey (1990) at the time were among the first to apply these principles also to movement coordination. Specifically, a synergy in the context of movement is defined as a functional assembly of (sub)components (e.g., neurons, muscles, joints) that are temporarily coupled or assembled in a task-specific manner, thus constrained to act as a single coordinated unit (or a coordinative structure; Kelso, 1995 ; Kelso et al., 2009 ). In motor control literature, the concept of coordinative structures or functional synergies are typically modeled as (non-linear) oscillatory systems ( Kelso, 1995 ; Newell et al., 2003 ; Profeta and Turvey, 2018 ). By strengthening or weakening the coupling within and between the system’s interacting (sub)components, synergies may be tuned or altered. For movement control, the synergy tuning process occurs with development and learning or may change due to task demands or constraints (e.g., Smith and Thelen, 2003 ; Kelso et al., 2009 ).

With regards to speech production, perturbation paradigms similar to the ones used in other motor control studies have demonstrated critical features of oral articulatory synergies (e.g., Folkins and Abbs, 1975 ; Kelso and Tuller, 1983 ; van Lieshout and Neufeld, 2014 ), which in AP terms can be referred to as gestures. Functional synergies in speech production comprise of laryngeal and supra-laryngeal structures (tongue, lips, jaw) coupled to achieve a single constriction (location and degree) goal. Perturbing the movement of one structure will lead to compensatory changes in all functionally coupled structures (including the articulator that is perturbed) to achieve the synergistic goal ( Kelso and Tuller, 1983 ). For example, when the jaw is perturbed in a downward direction during a bilabial stop closure, there is an immediate compensatory lowering of the upper lip and an increased compensatory elevation of the lower lip ( Folkins and Abbs, 1975 ). The changes in the nature and stability of movement coordination patterns (i.e., within and between specific speech motor synergies) as they evolve through time can be captured quantitatively via order parameters such as relative phase. Relative phase values are expressed in degrees or radians, and the standard deviation of relative phase values can provide an index of the stability of the couplings ( Kelso, 1995 ; van Lieshout, 2004 ). Whilst order parameters capture the relationship between the system’s interacting (sub)components, changes in order parameter dynamics can be triggered by alterations in a set of control parameters. For example, changes in movement rate may destabilize an existing coordination pattern and result in a different coordination pattern as observed during gait changes (such as switching from a walk to a trot and then a gallop) as a function of required locomotion speed ( Hoyt and Taylor, 1981 ; Kelso, 1995 ). For speech, such distinct behavioral patterns as a function of rate have not been established. However, in the coordination between lower jaw, upper and lower lip as part of a lip closing/opening synergy, typical speakers have shown a strong tendency for reduced covariance in the combined movement trajectory, despite individual variation in the actual sequence and timing of individual movements ( Alfonso and van Lieshout, 1997 ). This can be considered a characteristic of an efficient synergy. The same study also included people who stutter and reported more instances of not showing reduced covariance in this group, in line with the notion that stuttering is related to limitations in speech motor skill ( van Lieshout et al., 2004 ; Namasivayam and van Lieshout, 2011 ).

Recent work has provided more insights regarding cortical networks in control of this coordination between speech articulators ( Bouchard et al., 2013 ; Chartier et al., 2018 ). Chartier et al. (2018) mapped acoustic and articulatory kinematic trajectories to neural electrode sites in brains of patients, as part of their clinical treatment of epilepsy. Similar to limb control studies that discovered single motor cortical neurons that encoded complex coordinated arm and hand movements ( Aflalo and Graziano, 2006 ; Saleh et al., 2012 ), coordinated movements involving articulators for specific vocal-tract configurations were encoded at the single electrode level in the ventral sensorimotor cortex (vSMC). That is, activity in the vSMC reflects the synergies used in speech production rather than individual movements. Interestingly, the study found four major clusters of articulatory kinematic trajectories that encode the main vocal tract configurations (labial, coronal, dorsal, and vocalic) necessary to broadly represent the production of American English sounds. The encoded articulatory kinematic trajectories exhibited damped oscillatory dynamics as inferred from articulatory velocity and displacement relationships (phase portraits). These findings support theories that envision vocal tract gestures as articulatory units of speech production characterized by damped oscillatory dynamics [ Fowler et al., 1980 ; Browman and Goldstein, 1989 ; Saltzman and Munhall, 1989 ; see Section Articulatory Phonology and Speech Sound Disorders (SSD) in Children].

The notion of gestures at the level of speech perception has been discussed in the Theory of Direct Perception ( Fowler, 1986 ; Fowler and Rosenblum, 1989 ). This theory posits that listeners perceive attributes of vocal tract gestures, arguing that this reflects the common code shared by both the speaker and listener ( Fowler, 1986 , 1996 , 2014 ; Fowler and Rosenblum, 1989 ). These concepts are supported by a line of research studies which propose that the minimal objects of speech perception reflect gestures realized by the action of coordinative structures as transmitted by changes to the acoustic (and visual) signal, rather than units solely defined by a limited set of specific acoustic features ( Diehl and Kluender, 1989 ; Fowler and Rosenblum, 1989 ; Fowler, 1996 ). The Direct Perception theory thus suggests that speech perception is driven by the structural global changes in external sensory signals that allow for direct recognition of the original (gesture) source and does not require special speech modules or the need to invoke the speech motor system ( Fowler and Galantucci, 2005 ). Having a common unit for production and perception provides a useful framework to understand the broader nature of both sensory and motor involvement in speech disorders. For example, this can inform future studies to investigate how problems in processing acoustic information and thus perceiving the gestures from the speaker, may interfere with the tuning of gestures for production during development. Similarly, issues related to updating the state of the vocal tract through somato-sensory feedback (a critical component in TD; Saltzman and Munhall, 1989 ; Parrell et al., 2019 ) during development may also lead to the mistuning of gestures in production, potentially leading to the type of errors in vocal tract constriction degree and/or location as discussed in Section “Articulatory Phonology and Speech Sound Disorders (SSD) in Children.” However, for the current paper, the focus will be on production aspects only.

Development of Speech Motor Synergies

In this section, we will discuss the development and refinement of articulatory synergies and how these processes facilitate the emergence of speech sound contrasts. Observational and empirical data from several speech motor studies (as discussed below) were synthesized to create the timeline map of the development and refinement of speech motor control and articulatory synergies as illustrated in Figure 1 . Articulatory synergies in infants have distinct developmental schedules. Speech production in infants is thought to be restricted to sounds primarily supported by the mandible ( MacNeilage and Davis, 1990 ; Davis and MacNeilage, 1995 ; Green et al., 2000 ). Early mandibular movements (∼1 year or less) are ballistic in nature and restricted to closing and opening gestures due to the limited fine force control required for varied jaw heights ( Locke, 1983 ; Kent, 1992 ; Green et al., 2000 ). Vowel productions in the first year are generally related to low, non-front, and non-rounded vowels; implying that the tongue barely elevates from the jaw, and there is limited facial muscle (lip) interaction (i.e., synergy) with the jaw ( Buhr, 1980 ; Kent, 1992 ; Otomo and Stoel-Gammon, 1992 ; but see Giulivi et al., 2011 ; Diepstra et al., 2017 ).

Data driven timeline map of the development of speech motor control and articulatory synergies.

Sound sequences that do not require complex timing and coordination within/between articulatory gestures are easier to produce and the first to emerge ( Green et al., 2000 ; Green and Nip, 2010 ; Figure 1 ). For instance, young children are unable to coordinate laryngeal voicing gesture with supra-laryngeal articulation and hence master voiced consonants and syllables earlier than voiceless ones ( Kewley-Port and Preston, 1974 ; Grigos et al., 2005 ). The synergistic interaction between the laryngeal and supra-laryngeal structures underlying voicing contrasts is acquired closer to 2 years of age (∼20–23 months; Grigos et al., 2005 ), and follows the maturation of jaw movements (around 12–15 months of age; Green et al., 2002 ; Figure 1 ) and/or jaw stabilization ( Yu et al., 2014 ).

In children, up to and around 2 years of age, there is limited fine motor control of jaw height (or jaw grading) and weak jaw-lip synergies during bilabial production, but relatively stronger inter-lip spatial and temporal coupling ( Green et al., 2000 , 2002 ; Nip et al., 2009 ; Green and Nip, 2010 ). A possible consequence of these interactions is that their production of vowels is limited to that of extremes (high or low; /i/, /u/, /o/, and /ɑ/), and lip rounding/retraction is only present when the jaw is in a high position ( Wellman et al., 1931 ; Kent, 1992 ; Figure 1 ). As speech-related jaw-lip synergies are emerging, it is not surprising that children’s ability to execute lip rounding and retraction is possible when degrees of freedom can be reduced (i.e., when jaw is held in a high position). Observation of such a reduction in degrees of freedom in emerging synergies has been observed in other non-speech systems ( Bernstein, 1996 ). Interestingly, although the relatively strong inter-lip coordination pattern found in 2-year-olds is facilitative for bilabial productions, it needs to further differentiate to gain independent control of the functionally linked upper and lower lips prior to the emergence of labio-dental fricatives (/f/ and /v/; Green et al., 2000 ; Figure 1 ). This process is observed to occur between the ages of 2 and 3 years ( Stoel-Gammon, 1985 ; Green et al., 2000 ). Green et al. (2000 , 2002) suggest that upper and lower lip movements become adult-like with increasing contribution of the lower-lip toward bilabial closure between the ages of 2 and 6 years. Further control over jaw height (with the addition of /ε/ and /ɔ/) and lingual independence from the jaw is developed around 3 years of age ( Kent, 1992 ). The latter is evident from the production of reliable lingual gliding movements (diphthongs: /aʊ/, /ɔɪ/, and /aɪ) in the anterior-posterior dimension ( Wellman et al., 1931 ; Kent, 1992 ; Otomo and Stoel-Gammon, 1992 ; Donegan, 2013 ). Control of this dimension also coincides with the emergence of coronal consonants (e.g., /t/ and /d/; Smit et al., 1990 ; Goldman and Fristoe, 2000 ). By 4 years of age, all front and back vowels are within the spoken repertoire of children, suggesting a greater degree of control over jaw height and improved tongue-jaw synergies ( Kent, 1992 ). Intriguingly, front vowels and lingual coronal consonants emerge relatively late ( Wellman et al., 1931 ; Kent, 1992 ; Otomo and Stoel-Gammon, 1992 ). This is possibly due to the fine adjustments required by the tongue tip and blade to adapt to mandibular angles. Since velar consonants and back vowels are produced by the tongue dorsum, they are closer to the origin of rotational movement (i.e., condylar axis) and are less affected than the front vowels and coronal consonants ( Kent, 1992 ; Mooshammer et al., 2007 ). With maturation and experience, finer control over tongue musculature develops, and children begin to acquire rhotacized (retroflexed or bunched tongue) vowels (/ɝ/ and /ɚ/) and tense/lax contrasts ( Kent, 1992 ).

The later development of refined tongue movements is not surprising, since the tongue is considered a hydrostatic organ with distinct functional segments (e.g., tongue tip, tongue body; Green and Wang, 2003 ; Noiray et al., 2013 ). Gaining motor control and coordinating the tongue with neighboring articulatory gestures is difficult ( Kent, 1992 ; Smyth, 1992 ; Nittrouer, 1993 ). Cheng et al.’s (2007) study demonstrated a lower degree and more variable tongue tip to jaw temporal coupling in 6- to 7-year-old children relative to adults ( Figure 1 ). This contrasts with the earlier developing lip-jaw synergy reported by Green et al. (2000) , wherein by 6 years of age, children’s temporal coupling of lip and jaw was similar to adults. The coordination of the tongue’s subcomponents follows different maturation patterns. By 4–5 years, synergies that use the back of the tongue to assist the tongue tip during alveolar productions are adult-like ( Noiray et al., 2013 ), while synergies relating to tongue tip release and tongue body backing are not fully mature ( Nittrouer, 1993 ; Figure 1 ). The extent and variability of lingual vowel-on-consonant coarticulation between 6 and 9 years of age is greater than in adults; implying that children are still refining their tuning of articulatory gestures ( Nittrouer, 1993 ; Nittrouer et al., 1996 , 2005 ; Cheng et al., 2007 ; Zharkova et al., 2011 ).

These findings suggest that articulatory synergies have varying schedules of development: lip-jaw related synergies develop earlier than tongue-jaw or within tongue-related synergies ( Cheng et al., 2007 ; Terband et al., 2009 ). Most of this work has been done on intra-gestural coordination (i.e., between individual articulators within a gesture), but it is clear that both the development of intra- and inter-gestural synergies are non-uniform and protracted ( Whiteside et al., 2003 ; Smith and Zelaznik, 2004 ). Variability of intra-gestural synergies (e.g., upper- and lower-lip or lower lip–jaw) in 4- and 7-year-olds has been found to be greater than with adults but decreases with age until it plateaus between 7 and 12 years ( Smith and Zelaznik, 2004 ). Adult-like patterns are reached at around 14 years, and likely continuously refine and stabilize even up to the age of 30 years ( Smith and Zelaznik, 2004 ; Schötz et al., 2013 ; Figure 1 ). Overall, these findings suggest that the development of speech motor control is hierarchical, sequential, non-uniform, and protracted.

Gestures, Synergies and Linguistic Contrast

As mentioned above, within the AP model, the fundamental units of speech are articulatory “gestures.” Articulatory “gestures” are higher-level abstract specifications for the formation and release of task-specific, linguistically relevant vocal tract constrictions. The specific goals of each gesture are defined as Tract Variables ( Figure 2 ) and relate to vocal tract constriction location (labial, dental, alveolar, postalveolar, palatal, velar, uvular, and pharyngeal) and constriction degree (closed, critical, narrow, mid, and wide; Figure 2 ). While constriction degree is akin to manner of production (e.g., fricatives /s/ and /z/ are assigned a “critical” value; stops /p/ and /b/ are given a “closed” value), constriction location allows for distinctions in place of articulation ( Browman and Goldstein, 1992 ; Gafos, 2002 ).

A schematic representation of the AP model with key components ( Nam and Saltzman, 2003 ; Goldstein et al., 2007 ). TT, tongue tip; TB, tongue body; CD, constriction degree; CL, constriction location; Vel (or V in panel 3), Velum; GLO (or G in panel 3), glottis; LA, lip aperture; LP, lip protrusion (see text for more details).

The targets of each Tract Variable are implemented by specifying the lower-level functional synergy of individual articulators (e.g., articulator set of lip closure gesture: upper lip, lower lip, jaw) and their associated muscles ensembles (e.g., orbicularis oris, mentalis, risorius), which allows for the flexibility needed to achieve the task goal ( Saltzman and Kelso, 1987 ; Browman and Goldstein, 1992 ; Alfonso and van Lieshout, 1997 ; Gafos, 2002 ; Figure 2 ). The coordinated actions of the articulators toward a particular value (target) of a Tract Variable is modeled using damped mass spring equations ( Saltzman and Munhall, 1989 ). The variables in the equations specify the final position, the time constant of the constriction formation (i.e., the speed at which the constriction should be formed; stiffness), and a damping factor to prevent articulators from overshooting their targets ( Browman and Goldstein, 1989 ; Kelso et al., 1986a , b ; Saltzman and Munhall, 1989 ). For example, if the goal is to produce constriction at the lips (bilabial closure gesture), then the distance between the upper lip and lower lip (lip aperture) is set to zero. The resulting movements of individual articulators lead to changes in vocal tract geometry, with predictable aerodynamic and acoustic consequences.

The flexibility within the functional articulatory synergy implies that the task-level goals could be achieved with quantitatively different contributions from individual articulatory components as observed in response to articulatory perturbations or in adaptation to the linguistic context in which the gesture is produced ( Saltzman and Kelso, 1987 ; Browman and Goldstein, 1992 ; Alfonso and van Lieshout, 1997 ; Gafos, 2002 ). In other words, the task-level goals are discrete, invariant or context-free, but the resulting articulatory motions are context-dependent ( Browman and Goldstein, 1992 ). Gestures are phonological primitives that are used to achieve linguistic contrasts when combined into larger sequences (e.g., segments, words, phrases). The presence or absence of a gesture, or changes in gestural parameters like constriction location results in phonologically contrastive units. For example, the difference between “bad” and “ban” is the presence of a velum gesture in the latter, while “bad” and “pad” are differentiated by adding a glottal gesture for the onset of “bad”. Parameter differences in gestures such as the degree of vocal tract constriction yields phonological contrast by altering manner of production (e.g., “but” and “bus”; tongue tip constriction degree: complete closure for /t/ vs. a critical opening value to result in turbulence for /s/) ( Browman and Goldstein, 1986 , 1992 ; van Lieshout et al., 2008 ).

Gestures have an internal temporal structure characterized by landmarks (e.g., onset, target, release) which can be aligned to form segments, words, sentences and so on ( Gafos, 2002 ). These gestures and their timing relationships are represented by a gestural score in the AP model ( Figure 2 ; Browman and Goldstein, 1992 ). Gestural scores are estimated from articulatory kinematic data or speech acoustics by locating kinematic/acoustic landmarks to determine the timing relationships between gestures ( Nam et al., 2012 ). The timing relationships in the gestural score are typically expressed as relative phase values ( Kelso et al., 1986a , b ; van Lieshout, 2004 ). Words may differ by altering the relative phasing between their component gestures. For example, although the gestures are identical in “pat” and “tap,” the relative phasing between the gestures are different ( Saltzman and Byrd, 2000 ; Saltzman et al., 2006 ; Goldstein et al., 2007 ). As mentioned above, the coordination between individual gestures in a sequence is referred to as inter-gestural coupling/coordination ( van Lieshout and Goldstein, 2008 ). Inter-gestural level timing is not rigidly specified across an entire utterance but is sensitive to peripheral (articulatory) events ( Saltzman et al., 1998 ; Namasivayam et al., 2009 ; Tilsen, 2009 ). The presence of a coupling between inter-gestural level timing oscillators and feedback signals arising from the peripheral articulators was identified in experimental work by Saltzman et al. (1998) . In that study, unanticipated lip perturbation during discrete and repetitive production of the syllable /pa/ resulted in phase-shifts in the relative timing between the two independent gestures (lip closure and laryngeal closure) for the phoneme /p/ and between successive /pa/ syllables ( Saltzman et al., 1998 ). This confirms the critical role of somato-sensory information in the TD model ( Saltzman and Munhall, 1989 ; Parrell et al., 2019 ).

Dynamical systems can express different self-organizing coordination patterns, but for many systems, certain patterns of coordination seem to be preferred over others. These preferred patterns are induced by “attractors” ( Kelso, 1995 ), which reflect stable states in the coupling dynamics of such a system 2 . The coupling relationships used in speech production are similar to those identified for limb control systems ( Kelso, 1995 ; Goldstein et al., 2006 ) and capitalize on intrinsically stable modes of coordination (specifically, in-phase and anti-phase modes; Haken et al., 1985 ). These are patterns that are naturally achieved without training or learning; however, they are not equally stable ( Haken et al., 1985 ; Nam et al., 2009 ). In-phase coordination patterns, for instance, are relatively more stable than anti-phase patterns ( Haken et al., 1985 ; Kelso, 1995 ; Goldstein et al., 2006 ). Other coordination patterns are possible, but they are more variable, may require higher energy expenditure and can only be acquired with significant training ( Kelso, 1984 ; Peper et al., 1995 ; Peper and Beek, 1998 ; Nam et al., 2009 ). For example, when participants are asked to oscillate two limbs or fingers, they spontaneously switch coordination patterns from the less stable anti-phase to the more stable in-phase as the required movement frequency increases, but not vice versa ( Kelso, 1984 ; Haken et al., 1985 ; Peper et al., 2004 ). These two modes of coordination likely form the basis of syllable structure ( Goldstein et al., 2006 ). The onset consonant (C) and vowel (V) planning oscillators (see below) are said to be coupled in-phase, while the CC onset clusters and the nucleus (V) and coda (C) gestures are coupled in anti-phase mode. As the in-phase coupling mode is more stable, this can explain the dominance of CV syllable structure during babbling and speech development as well as across languages ( Goldstein et al., 2006 ; Nam et al., 2009 ; Giulivi et al., 2011 ).

Using the TD framework in the AP model ( Nam and Saltzman, 2003 ), speech production planning processes and dynamic multi-frequency coupling between gestural and rhythmic (prosodic) systems have been explained using the notion of coupled oscillator models ( Goldstein et al., 2006 ; Nam et al., 2009 ; Tilsen, 2009 ; Gafos and Goldstein, 2012 ). The coupled oscillator models for speech gestures are associated with non-linear (limit cycle) planning level oscillators which can be coordinated in relative time by specifying a phase relationship between them. During an utterance, the planning oscillators for multiple gestures generate a representation of the various (and potentially competing) coupling specifications, referred to as a coupling graph ( Figure 2 ; Saltzman et al., 2006 ). The activation of each gesture is then triggered by its respective oscillator after they settle into a stable pattern of relative phasing during the planning process ( van Lieshout and Goldstein, 2008 ; Nam et al., 2009 ). In this manner, the coupled oscillator model has been used to control the relative timing of multiple gestural activations during word or sentence production. To recap, individual gestures are modeled as critically damped mass-spring systems with a fixed-point attractor where speed, amplitude and duration are manipulated by adjustments to dynamic parameter specifications (e.g., damping and stiffness variables). In contrast, gestural planning level systems are modeled using limit cycle oscillators and their relative phases are controlled by potential functions ( Tilsen, 2009 ; Pouplier and Goldstein, 2010 ).

Similar to the bidirectional relationship between inter-gestural timing and peripheral articulatory state, interactions between gestural and rhythmic level oscillators have also been noted. To explain the dynamic interactions between gestural and rhythmic (stress and prosody) systems, speech production may rely on a similar multi-frequency system of coupled oscillators as proposed for limb movements ( Peper et al., 1995 ; Tilsen, 2009 ). The coupling strength and stability in such systems varies not only as a function of type of phasing (in-phase or anti-phase), but also by the complexity of coupling (ratio of intrinsic oscillator frequencies of the coupled structures), movement amplitude and the movement rate at which the coupling needs to be maintained ( Peper et al., 1995 ; Peper and Beek, 1998 ; van Lieshout and Goldstein, 2008 ; van Lieshout, 2017 ). For example, rhythmic movement between the limbs has been modeled as a system of coupled oscillators that exhibit (multi)frequency locking. The most stable coupling mode is when two or more structures (oscillators) are frequency locked in a lower-order (e.g., 1:1) ratio. Multi-frequency locking for upper limbs is possible at higher order ratios of 3:5 or 5:2 (e.g., during complex drumming) but only at slower movement frequencies. As the required movement rate increases, the complex frequency coupling ratios will exhibit transitions to simpler and inherently more stable ratios ( Peper et al., 1995 ; Haken et al., 1996 ). Studies on rhythmic limb coupling show that increases in movement frequency are inversely related to decreases in coupling strength and coordination stability. The increases in movement frequency or rate may be associated with a drop in the movement amplitude that mediates the differential loss of stability across the frequency ratios ( Haken et al., 1996 ; Goldstein et al., 2007 ; van Lieshout, 2017 ). However, smaller movement amplitude in itself (independent from duration and rate) can also decrease coupling strength and coordination stability ( Haken et al., 1985 ; Peper et al., 2008 ; van Lieshout, 2017 ). Amplitude changes are presumably used to stabilize the output of a coupled neural oscillatory system. Smaller movement amplitudes may decrease feedback gain, resulting in a reduction of the neural oscillator-effector coupling strength and stability ( Peper and Beek, 1998 ; Williamson, 1998 ; van Lieshout et al., 2004 ; van Lieshout, 2017 ). Larger movement amplitudes facilitate neural phase entrainment by enhancing feedback signals, but a certain minimum sensory input is required for entrainment to occur ( Williamson, 1998 ; Ridderikhoff et al., 2005 ; Peper et al., 2008 ; Kandel, 2013 ; van Lieshout, 2017 ). Several studies have demonstrated the critical role of movement amplitude on coordination stability in different types of speech disorders such as stuttering and apraxia ( van Lieshout et al., 2007 ; Namasivayam et al., 2009 ; for review see Namasivayam and van Lieshout, 2011 ).

Such complex couplings between multi-frequency oscillators may be found at different levels in the speech system such as between slower vowel production and faster consonantal movements ( Goldstein et al., 2007 ), or between shorter-time scale gestures and longer-time scale rhythmic units (moras, syllables, feet and phonological phrases; Tilsen, 2009 ). Experimentally, the interaction between gestural and rhythmic systems have been identified by a high correlation between inter-gestural temporal variability and rhythmic variability ( Tilsen, 2009 ), while behaviorally, such gesture-rhythm interactions are supported by observations of systematic relationships between patterns of segment and syllable deletions, and stress patterns in a language ( Kehoe, 2001 ; for an alternative take on neutralization in strong positions using constraint-based theory and AP model see McAllister Byun, 2011 ). Issues in maintaining the stability of complex higher order ratios in multi-frequency couplings (especially at faster speech rates) between slower vowel production and faster consonantal movements have also been implicated in the occurrence of speech sound errors in healthy adult speakers ( Goldstein et al., 2007 ). More about this aspect in the next section.

The development of gestures is tied to organs of constriction in two ways: between-organ and within-organ differentiation ( Goldstein and Fowler, 2003 ). There is empirical data to support that these differentiations occur over developmental timelines ( Cheng et al., 2007 ; Terband et al., 2009 ; see Section Development of Speech Motor Synergies). When a gesture corresponds to different organs (e.g., bilabial closure implemented via upper and lower lip plus jaw), between-organ differentiation is observed at an earlier stage in development. For within-organ differentiation, children must learn that for a given organ, different gestures may require different variations in vocal tract constriction location and degree. For example, /d/ and /k/ are produced by the same constriction organ (tongue) but use different constriction locations (alveolar vs. velar). Within-organ differentiation is said to occur at a later stage in development via a process called attunement ( Studdert-Kennedy and Goldstein, 2003 ). During the attunement process, initial speech gestures produced by an infant (i.e., based on between organ contrasts) become tailored (attuned) toward the perceived finer grained differentiations in gestural patterns in the ambient language (e.g., similar to phonological attunement proposed by Shriberg et al., 2005 ). In sum, gestural planning, temporal organization of gestures, parameter specification of gestures, and gestural coupling (between gestures, and between gestures and other rhythmic units) result in specific behavioral phenomena including casual speech alternations (e.g., syllable deletions, assimilations), as will be discussed next.

Describing Casual Speech Alternations

The AP model accounts for variations and errors in the speech output by demonstrating how the task-specific gestures at the macroscopic level are related to the systematic changes at the microscopic level of articulatory trajectories and resulting speech acoustics (e.g., speech variability, coarticulation, allophonic variation, and speech errors in casual connected speech; Saltzman and Munhall, 1989 ; Browman and Goldstein, 1992 ; Goldstein et al., 2007 ). Browman and Goldstein (1990b) argue that speech sound errors such as consonant deletions, assimilations, and schwa deletions can result from an increasing overlap between different gestures, or from reducing the size (magnitude) of articulatory gestures (see also van Lieshout and Goldstein, 2008 ; Hall, 2010 ). The amount of gestural overlap is assumed to be a function of different factors, including style (casual vs. formal speech), the organs used for making the constrictions, speech rate, and linguistic constraints ( Goldstein and Fowler, 2003 ; van Lieshout and Goldstein, 2008 ).

The gestural processes surrounding consonant and schwa deletions can be explained by alterations in gestural overlap resulting from changes in relative timing or phasing in the gestural score. The gestural overlap has different consequences in the articulatory and acoustic output, depending on whether the gestures share the same Tract Variables and corresponding articulatory sets (homorganic) or whether they employ different Tract Variables and constricting organs (heterorganic). Heterorganic gestures (e.g., lip closure combined with a tongue tip closure) will result in a Tract Variable motion for each gesture that is unaffected by the other concurrent gesture; and their Tract Variables goals will be reached, regardless of the degree of overlap. However, when maximum overlap occurs, one gesture may completely obscure or hide the other gesture acoustically during release (i.e., gestural hiding; Browman and Goldstein, 1990b ). In homorganic gestures, when two gestures share the same Tract Variables and articulators, as in the case of a tongue tip (TT) constriction to produce /θ/ and /n/ (e.g., during production of /tεn θimz/) they perturb each other’s Tract Variable motions. The dynamical parameters of the two overlapping gestural control regimes are ‘blended.’ These gestural blendings are traditionally described phonologically as assimilation (e.g., /tεn θimz/ → [tεn̪ θimz]) or allophonic variations (e.g., front and back variation of /k/ in English: “ key ” and “ caw ”; Ladefoged, 1982 ) ( Browman and Goldstein, 1990a , b ).

Articulatory kinematic data collected using an X-Ray Microbeam system (e.g., Browman and Goldstein, 1990b ) have provided support for the occurrence of these gestural processes (hiding and blending). Consider the following classic examples in the literature ( Browman and Goldstein, 1990b ). The production of the sequence “nabbed most” is usually heard by the listener as “nab most” and the spectrographic display reveals no visible presence of /d/. However, the presence of the tongue tip raising gesture for /d/ can be seen in X-ray data ( Browman and Goldstein, 1990b ), but it is inaudible and completely overlapped by the release of the bilabial gestures /b/ and /m/ ( Hall, 2010 ). Similarly, in fast speech, words like “ potential” sound like “ptential,” wherein the first schwa between the consonants /p/ and /t/ seems to be omitted, but in fact is hidden by the acoustic release of /p/ and /t/ ( Byrd and Tan, 1996 ; Davidson, 2006 ; Hall, 2010 ). These cases show that relevant constrictions are formed, but they are acoustically and perceptually hidden by another overlapping gesture ( Browman and Goldstein, 1990b ). Assimilations have also been explained by gestural overlap and gesture magnitude reduction. In the production of “ seven plus seven ,” which often sounds like “ sevem plus seven ,” the coronal nasal consonant /n/ appears to be replaced by the bilabial nasal /m/ in the presence of the adjacent bilabial /p/. In reality, the tongue tip /n/ gesture is reduced in magnitude and overlapped by the following bilabial gesture /p/ ( Browman and Goldstein, 1990b ; Hall, 2010 ). The AP model accounts for rate-dependent speech sound errors by gestural overlap and gestural magnitude reduction ( Browman and Goldstein, 1990b ; Hall, 2010 ). Auditory-perceptual based transcription procedures would describe the schwa elision and consonant deletion (or assimilation processes) in the above examples by a set of phonological rules schematically represented as d →∅/C_C (i.e., /d/ is deleted in the presence of two adjacent consonants in “nabbed most” → “nab most” ; Hall, 2010 ). However, these rules do not capture the fact that movements for the /d/ or /n/ are still present. Furthermore, articulatory data indicate that such speech sound errors are often not the result of whole-segment or feature substitutions/deletions, but are due to co-production of unintended or intrusion gestures to maintain the dynamic stability in the speech production system instead ( Pouplier and Goldstein, 2005 ; Goldstein et al., 2007 ; Pouplier, 2007 , 2008 ; Slis and van Lieshout, 2016a , b ).

The concept of intrusion gestures is illustrated with kinematic data from Goldstein et al. (2007) study where participants repeated bisyllabic sequences such as “cop top” at fast and slow speech rate conditions. Goldstein et al. (2007) noticed unique speech sound errors in that both the intended and extra/unintended (intruding) gestures were produced at the same time. True substitutions and deletions of the targets occurred rarely, even though, substitution errors are the most commonly reported error type in speech sound error studies when using auditory-perceptual transcription procedures ( Dell et al., 2000 ). Goldstein et al. (2007) explained their findings based on the DST concepts of stable rhythmic synchronization and multi-frequency locking (see Section Gestures, Synergies and Linguistic Contrast). The word pairs “cop top” differ in their onset consonant but share the syllable rhyme. Thus, each production of “cop top” contains one tongue tip (/t/), one tongue dorsum (/k/) gesture, but two labial (/p/) gestures. This results in the initial consonants being in a 1:2 relationship with the coda consonant. Such multi-frequency ratios are intrinsically less stable ( Haken et al., 1996 ), especially under fast rate conditions. As speech rate increased, they observed an extra copy of tongue tip inserted or co-produced during the /k/ production in “cop” and a tongue dorsum intrusion gesture during the /t/ production in “top.” Adding an extra gesture (the intrusion) results in a more stable harmonic relationship where both the initial consonants (tongue tip and tongue dorsum gestures) are in a 2:2 (or 1:1) relationship with the coda (lip gestures) consonant ( Pouplier, 2008 ; Slis and van Lieshout, 2016a , b ). Thus, gestural intrusion errors can be described as resulting from a rhythmic synchronization process, where the more complex and less stable 1:2 frequency-locked coordination mode is dissolved and replaced by a simpler and intrinsically more stable 1:1 mode by adding gestures. Unlike what is claimed for perception-based speech sound errors (e.g., Dell et al., 2000 ), the addition of “extra” cycles of the tongue tip and/or tongue dorsum oscillators results in phonotactically illegal simultaneous articulation of /t/ and /k/ ( Goldstein et al., 2007 ; Pouplier, 2008 ; van Lieshout and Goldstein, 2008 ; Slis and van Lieshout, 2016a , b ). The fact that /kt/ co-production is phonotactically illegal in English makes it difficult for a listener to even detect its presence. Pouplier and Goldstein (2005) further suggest that listeners only perceive intrusions that are large in magnitude (frequently transcribed as segmental substitutions errors), while smaller gestural intrusions are not heard, and targets are scored as error-free despite conflicting articulatory data ( Pouplier and Goldstein, 2005 ; Goldstein et al., 2007 ; see also Mowrey and MacKay, 1990 ).

Articulatory Phonology and Speech Sound Disorders (SSD) in Children

In this section, we briefly describe the patterns of speech sound errors in children as they have been typically discussed in the S-LP literature. This is followed by an explanation of how the development, maturation, and the combinatorial dynamics of articulatory gestures (such as phasing or timing relationships, coupling strength and gestural overlap) can offer a well-substantiated explanation for several of these more atypical speech sound errors. We will provide a preliminary and arguably, tentative mapping between several subtypes of SSDs in children and their potential origins as explained in the context of the AP and TD framework ( Table 1 ). We see this as a starting point for further discussion and an inspiration to conduct more research in this specific area. For example, one could use the AP/TD model (TADA; Nam et al., 2004 ) to simulate specific problems at the different levels of the model to systematically probe the emerging symptoms in movement and acoustic characteristics and then verify those with actual data, similar to recent work on apraxia and stuttering using the DIVA framework ( Civier et al., 2013 ; Terband et al., 2019b ). Since there is no universally agreed-upon classification system in speech-language pathology, we will limit our discussion to the SSD classification system proposed by Shriberg (2010 ; Vick et al., 2014 ; see Waring and Knight, 2013 for a critical evaluation of the current childhood SSD classification systems) and phonological process errors as described in the widely used clinical assessment tool Diagnostic Evaluation of Articulation and Phonology (DEAP; Dodd et al., 2006 ). We will refer to these phonological error patterns as process errors/speech sound error patterns, in line with their contemporary usage as descriptive terms, without reference to phonological or phonetic theory underpinnings.

Depicts speech sound disorder classification (and subtypes; based on Vick et al., 2014 ; Shriberg, 2017 ), most commonly noted error types, examples, and proposed levels of breakdown or impairment within the Articulatory Phonology model and Task Dynamics Framework ( Saltzman and Munhall, 1989 ; Browman and Goldstein, 1992 ).

Speech Delay

According to Shriberg et al. (2010) and Shriberg et al. (2017) , children with Speech Delay (age of occurrence between 3 and 9 years) are characterized by “delayed acquisition of correct auditory–perceptual or somatosensory features of underlying representations and/or delayed development of the feedback processes required to fine tune the precision and stability of segmental and suprasegmental production to ambient adult models” ( Shriberg et al., 2017 , p. 7). These children present with age-inappropriate speech sound deletions and/or substitutions, among which patterns of speech sound errors as described below:

Gliding and Vocalization of Liquids

Gliding is described as a substitution of a liquid with a glide (e.g., rabbit /ræbIt/ → [wæbIt] or [jæbIt], please /pliz/ → [pwiz], look /lʊk/ → [wʊk]; McLeod and Baker, 2017 ) and vocalization of liquids refers to the substitution of a vowel sound for a liquid (e.g., apple /æpl/ → [æpʊ], bottle /bɑtl/ → [bɑtʊ]; McLeod and Baker, 2017 ). The /r/ sounds are acoustically characterized by a drop in the third formant ( Alwan et al., 1997 ). In terms of movement kinematics the /r/ sound is a complex coproduction of three vocal tract constrictions/gestures (i.e., labial, tongue tip/body, and tongue root), requires a great deal of speech motor skill, and is mastered by most typically developing children between 4 and 7 years of age ( Bauman-Waengler, 2016 ). Ultrasound data suggests that children may find the simultaneous coordination of three gestures motorically difficult and may simplify the /r/ production by dropping one gesture from the segment ( Adler-Bock et al., 2007 ). Moreover, the syllable final /r/ sounds are often substituted with vowels because they share only a subset of vocal tract constrictions with the original /r/ sound and this is better described as a simplification process ( Adler-Bock et al., 2007 ). For example, the child may drop the tongue tip gesture but retain the lip rounding gesture and the latter dominates resulting vocal tract acoustics ( Adler-Bock et al., 2007 ; van Lieshout et al., 2008 ). Kinematic data derived from electromagnetic articulography ( van Lieshout et al., 2008 ) also points to a limited within-organ differentiation of the tongue parts and subtle issues in relative timing between different components of the tongue in /r/ production errors. These arguments also have support from longitudinal observational data on positional lateral gliding in children (/l/ is realized as [j]; Inkelas and Rose, 2007 ). Positional lateral gliding in children is said to occur when the greater gestural magnitude of prosodically strong onsets in English interacts with the anatomy of the child’s vocal tract ( Inkelas and Rose, 2007 ; McAllister Byun, 2011 , 2012 ). Within the AP model, reducing the number of required gestures (simplification) and poor tongue differentiation issues would likely have their origins at the level of Tract Variables while issues in relative timing between the tongue gestures are likely to arise at the level of the Gestural Score ( Table 1 ).

Stopping of Fricatives

Stopping of fricatives involves a substitution of a fricative consonant with a homorganic plosive (e.g., zoo /zu/ → [du], shoe /ʃu/ → [tu], see /si/ → [ti]; McLeod and Baker, 2017 ). Fricatives are another class of late acquired sounds that require precise control over different parts of the tongue to produce a narrow groove through which turbulent airflow passes. Within the AP model, the stopping of fricatives may arise from an inappropriate Tract Variable constriction degree specification (Constriction Degree: /d/ closed vs. /z/ critical; Goldstein et al., 2006 ; see Table 1 ), possibly as a simplification process secondary to limited precision of tongue tip control. Alternatively, neutralization (or stopping) of fricatives especially in prosodically strong contexts has also been explained from a constraint-based grammar perspective. For example, the tendency to overshoot is greater in initial positions where a more forceful gesture is favored for prosodic reasons. This allows the hard to produce fricative to be replaced by a ballistic tongue-jaw gesture that does not violate the MOVE-AS-UNIT constraint ( Inkelas and Rose, 2007 ; McAllister Byun, 2011 , 2012 ) as described in the “Introduction Section.”

Vowel Addition and Final Consonant Deletion

Different types of vowel insertion errors have been observed in children’s speech. An epenthesis is typically a schwa vowel inserted between two consonants in a consonant cluster (e.g., please /pliz/ → [pəliz] CCVC → CVCVC; blue /blu/ → [bəlu] CCV → CVCV), while other types of vowel insertions have also been noted (e.g., bat /bæt/ → [bæta]; CVC → CVCV) ( McLeod and Baker, 2017 ). A final consonant deletion involves the deletion of a consonant in a syllable or word final position (seat /sit/ → [si], cat /cæt/ → [cæ], look /lʊk/ → [lʊ]; McLeod and Baker, 2017 ). Both these phenomena could be explained by the concept of relative stability. As noted earlier, the onset consonant and the vowel (CV) are coupled in a relatively more stable in-phase mode as opposed to the anti-phase VC and CC gestures ( Goldstein et al., 2006 ; Nam et al., 2009 ; Giulivi et al., 2011 ). Thus, the maintenance of relative stability in VC or CC coupling modes may be more difficult with increasing cognitive-linguistic (e.g., vocabulary growth) or speech motor demands (e.g., speech rate), and there may be a tendency to utilize intrusion gestures as a means to stabilize the speech motor system (i.e., by decreasing frequency locking ratios; e.g., 2:1 to 1:1; Goldstein et al., 2007 ). We suspect that such mechanisms underlie vowel intrusion (error) gestures in children. In CVC syllables (or word structures), greater stability in the system may be achieved by dropping or deleting the final consonant and thus retaining the more stable in-phase CV coupling ( Goldstein et al., 2006 ). Moreover, findings from ultrasound tongue motion data during the production of repeated two- and three-word phrases with shared consonants in coda (e.g., top cop) versus no-coda positions (e.g., taa kaa, taa kaa taa) have demonstrated a gestural intrusion bias only for the shared coda consonant condition ( Pouplier, 2008 ). These findings suggest that the presence of (shared) coda consonants is a trigger for a destabilizing influence on the speech motor system ( Pouplier, 2008 ; Mooshammer et al., 2018 ). From an AP perspective, the stability induced by deleting final consonants or adding intrusion gestures (lowering frequency locking ratios) can be assigned to limitations in inter-gestural coordination and/or possible gestural selection issues at the level of Gestural Planning Oscillators ( Figure 2 ). We argue that (vowel) intrusion sound errors are not a “symptom” of an underlying (phonological) disorder, but rather the result of a compensatory mechanism for a less stable speech motor system. Additionally, children with limited jaw control may omit the final consonant /b/ in /bɑb/ in a jaw close-open-close production task, due to difficulties with elevating the jaw. This would typically be associated with the Tract Variable level in the AP model or at later stages during the specification of jaw movements at the Articulatory level (see Figure 2 and Table 1 ).

Cluster Reduction

Cluster reduction refers to the deletion of a (generally more marked) consonant in a cluster (e.g., please /pliz/ → [piz], blue /blu/ → [bu], spot /spɒt/ → [pɒt]; McLeod and Baker, 2017 ). From a stability perspective, CC onset clusters are less stable (i.e., anti-phasic) and in the presence of increased demands or limitations in the speech motor system (e.g., immaturity; Fletcher, 1992 ), they are more likely replaced by a stable CV coupling pattern by omitting the extra consonantal gesture ( Goldstein et al., 2006 ; van Lieshout and Goldstein, 2008 ; Nam et al., 2009 ). Alternatively, there is also the possibility that when two (heterorganic) gestures in a cluster are produced they may temporally overlap, thereby acoustically and perceptually hiding one gesture (i.e., gestural hiding; Browman and Goldstein, 1990b ; Hardcastle et al., 1991 ; Gibbon et al., 1995 ). Within the AP model, cluster reductions due to stability factors and gestural hiding may be ascribed to the Gestural Score Activation level (a gesture may not be activated in a CCV syllable to maintain stable CV structure) and to relative phasing issues (increased temporal overlap) at the level of inter-gestural coordination ( Figure 2 and Table 1 ; Goldstein et al., 2006 ; Nam et al., 2009 ).

Weak Syllable Deletion

Weak syllable deletion refers to the deletion of an unstressed syllable (e.g., telephone /tɛləfoʊn/ → [tɛfoʊn], potato /pəteɪtoʊ/ → [teɪtoʊ], banana /bənænə/ → [nænə]; McLeod and Baker, 2017 ). Multisyllabic words pose a unique challenge in that they comprise of complex couplings between multi-frequency syllable and stress level oscillators (e.g., Tilsen, 2009 ). Deleting an unstressed syllable in a multisyllabic word may allow reduction of complexity by frequency locking in a stable lower order-mode between syllable and stress level oscillators. Within the AP model, this process is regulated at the level of Gestural Planning Oscillators (see Table 1 ; Goldstein et al., 2007 ; Tilsen, 2009 ).

Velar Fronting and Coronal Backing

Fronting is defined as a substitution of a sound produced in the back of the vocal tract with a consonant articulated further toward the front (e.g., go /go/ → [do], duck /dk/ → [dt], key /ki/ → [ti]; McLeod and Baker, 2017 ). Backing on the other hand, is defined as a substitution of a sound produced in the front of the vocal tract with a consonant articulated further toward the back (e.g., two /tu/ → [ku], pat /pæt/ → [pæk], tan /tæn/ → [kæn]; McLeod and Baker, 2017 ). While fronting is frequently observed in typically developing young children, backing is rare for English-speaking children ( McLeod and Baker, 2017 ). Children who exhibit fronting and backing behaviors show evidence of undifferentiated lingual gestures, according to electropalatography (EPG) and electromagnetic articulography studies ( Gibbon, 1999 ; Gibbon and Wood, 2002 ; Goozée et al., 2007 ). Undifferentiated lingual gestures lack clear differentiation between the movements of the tongue tip, tongue body, and lateral margins of the tongue. For example, tongue-palate contact is not confined to the anterior part of the palate for alveolar targets, as in normal production. Instead, tongue-palate contact extends further back into the palatal and velar regions of the vocal tract ( Gibbon, 1999 ). It is estimated that 71% of children (aged 4-12 years) with a clinical diagnosis of articulation and phonological disorders produce undifferentiated lingual gestures. These undifferentiated lingual gestures are argued to arise from decreased oro-motor control abilities, a deviant compensatory bracing mechanism (i.e., an attempt to counteract potential disturbances in tongue tip fine motor control; Goozée et al., 2007 ) or may represent an immature speech motor system ( Gibbon, 1999 ; Goozée et al., 2007 ). Undifferentiated lingual gestures are not a characteristic of speech in typically developing older school-age children or adults ( Gibbon, 1999 ). In children’s productions of lingual consonants, there is a decrease in tongue-palate contact on EPG with increasing age (6 through 14 years) paralleled by fine-grained articulatory adjustments ( Fletcher, 1989 ). The tongue tip and tongue body function as two quasi-independent articulators in typical and mature speech production systems (see section Development of Synergies in Speech ). However, in young children, the tongue and jaw (tongue-jaw complex) and different functional parts of the tongue may be strongly coupled in-phase (i.e., always move together), and thus lack functionally independent regions ( Gibbon, 1999 ; Green et al., 2002 ). Undifferentiated lingual patterns may thus result from simultaneous (in-phase) activation of regions of the tongue and/or tongue-jaw complex in young children and persist over time ( van Lieshout et al., 2008 ).

Standard acoustic-perceptual transcription procedures do not reliably detect undifferentiated lingual gestures ( Gibbon, 1999 ). Undifferentiated lingual gestures are sometimes transcribed as phonetic distortions or phonological substitutions (i.e., velar fronting or coronal backing) in some contexts, but may be transcribed as correct productions in other contexts ( Gibbon, 1999 ; Gibbon and Wood, 2002 ). The perception of place of articulation of an undifferentiated gesture is determined by changes in tongue-palate contact during closure (i.e., articulatory drift; Gibbon and Wood, 2002 ). For example, closure might be initiated in the velar region, cover the entire palate, and then be released in the coronal or anterior region (or vice versa). Undifferentiated lingual gestures could therefore yield the perception of either velar fronting or coronal backing. The perceived place of articulation is influenced by the direction of the articulatory drift and the last tongue-palate contact region ( Gibbon and Wood, 2002 ). Children with slightly more advanced lingual control, relative to those described with widespread use of undifferentiated gestures, may still present with fine-motor control or refinement issues (e.g., palatal fronting /ʃ/ →[s]; backing of fricatives /s/ →[ʃ]; Gibbon, 1999 ). Velar fronting and coronal backing can be envisioned as incorrect in relative phasing at the level of inter-gestural coordination 3 (see Table 1 ). For instance, the tongue tip-tongue body or tongue-jaw complex may be in a tight synchronous in-phase coupling, but the release of constriction may not. It may also be a problem in Tract Variable constriction location specification ( Table 1 ).

Prevocalic Voicing and Postvocalic Devoicing

Context sensitive voicing errors in children are categorized as prevocalic voicing and postvocalic devoicing. Prevocalic voicing is a process in which voiceless consonants in syllable initial positions are replaced by voiced counterparts (e.g., pea /pi/ → [bi]; pan /pæn/ → [bæn]; pencil /pεnsəl/ → [bεnsəl]) and postvocalic devoicing is when voiced consonants in syllable final position are replaced by voiceless counterparts (e.g., Bag /bæg/ → [bæk], pig /pIg/ → [pIk]; seed /sid/ → [sit]; McLeod and Baker, 2017 ). Empirical evidence suggests that in multi-gestural segments, segment-internal coordination of gestures may be different in onset than in coda position ( Krakow, 1993 ; Goldstein et al., 2006 ). When a multi-gestural segment is produced in a syllable onset, such as a bilabial nasal stop (e.g., [m]), the necessary gestures (bilabial closure gesture, glottal gesture and velar gesture) are synchronously produced (i.e., in-phase), creating the most stable configuration for that combination of gesture; this makes the addition of voicing in onset position easy. However, in coda position, the bilabial closure gesture, glottal gesture (for voicing) and velar gesture must be produced asynchronously (i.e., in a less stable anti-phase mode; Haken et al., 1985 ; Goldstein et al., 2006 , 2007 ). It is thus less demanding to coordinate fewer gestures in the anti-phase mode across oral and laryngeal speech subsystems in a coda position. This would explain why children (with a developing speech motor system) may simply drop the glottal gesture (devoicing in coda position) to reduce complexity. Note, that in some languages (e.g., Dutch), coda devoicing is standard irrespective of the original voicing characteristic of that sound. Within the AP model, prevocalic voicing and postvocalic devoicing (i.e., adding or dropping a gesture) may be ascribed to gestural selection issues at the level of Gestural Planning Oscillators ( Figure 2 and Table 1 ).

Recent studies also suggest a relationship between jaw control and acquisition of accurate voice-voiceless contrasts in children. The production of a voice-voiceless contrast requires precise timing between glottal abduction/adduction and oral closure gestures. Voicing contrast acquisition in typically developing 1- to 2-year-old children may be facilitated by increasing the jaw movement excursion, speed and stability ( Grigos et al., 2005 ). In children with SSDs (including phonological disorder, articulation disorder and CAS) relative to typically developing children, jaw deviances/instability in the coronal plane (i.e., lateral jaw slide) have been observed ( Namasivayam et al., 2013 ; Terband et al., 2013 ). Moreover, stabilization of voice onset times for /p/ production has been noted in children with SSDs undergoing motor speech intervention focused on jaw stabilization ( Yu et al., 2014 ). These findings are not surprising given that the perioral (lip) area lacks tendon organs, joint receptors and muscle spindles ( van Lieshout, 2015 ), and the only reliable source of information to facilitate inter-gestural coordination between oral and laryngeal gestures comes from the jaw masseter muscle spindle activity ( Namasivayam et al., 2009 ). Increases in jaw stability and amplitude may provide consistent and reliable feedback used to stabilize the output of a coupled neural oscillatory system comprising of larynx (glottal gestures) and oral articulators ( van Lieshout, 2004 ; Namasivayam et al., 2009 ; Yu et al., 2014 ; van Lieshout, 2017 ).

Articulation Impairment

Articulation impairment is considered a motor speech difficulty and generally reserved for speech sound errors related to rhotics and sibilants (e.g., derhotacized /r/: bird /bɝd/ → [bɜd]; dentalized/lateralized sibilants: sun /sn/ → [ɬʌn] or [s̪ʌn]; McLeod and Baker, 2017 ). A child with an articulation impairment is assumed to have the correct phoneme selection but is imprecise in the speech motor specifications and implementation of the sound ( Preston et al., 2013 ; McLeod and Baker, 2017 ). Studies using ultrasound, EPG and electromagnetic articulography data have shown several aberrant motor patterns to underlie sibilant and rhotic distortions. For rhotics, these may range from undifferentiated tongue protrusion, absent anterior tongue elevation, absent tongue root retraction and subtle issues in relative timing between different components of the tongue gestures ( van Lieshout et al., 2008 ; Preston et al., 2017 ). Correct /s/ productions involve a groove in the middle of the tongue along with an elevation of the lateral tongue margins ( Preston et al., 2016 , 2017 ). Distortions in /s/ production may arise from inadequate anterior tongue control, poor lateral bracing (sides of the tongue down) and missing central groove ( McAuliffe and Cornwell, 2008 ; Preston et al., 2016 , 2017 ).

Within the AP model, articulation impairments may potentially arise at three levels: Tract Variables , Gestural Scores and dynamical specification of the gestures. We discussed rhotic production issues at the Tract Variables and Gestural Score levels in the Gliding and vocalization of liquids section as a reduction in the number of required gestures (i.e., some parts of the tongue not activated during /r/), limited tongue differentiation, and/or subtle relative timing issues between the different tongue gestures/components. Errors in dynamical specifications of the gestures could also result in speech sound errors. For example, incorrect damping parameter specification for vocal tract constriction degree may result in the Tract Variables (and their associated articulators) overshooting (underdamping) or undershooting (overdamping) their rest/target value ( Browman and Goldstein, 1990a ; Fuchs et al., 2006 ).

Childhood Apraxia of Speech (CAS)

The etiology for CAS is unknown, but it is hypothesized to be a neurological sensorimotor disorder with a disruption at the level of speech motor planning and/or motor programing of speech movement sequences (American Speech–Language–Hearing Association ( ASHA, 2007 ). A position paper by ASHA (2007) describes three important characteristics of CAS which include inconsistent speech sound errors on repeated productions, lengthened and disrupted coarticulatory transitions between sounds and syllables, and inappropriate prosody that includes both lexical and phrasal stress difficulties ( ASHA, 2007 ). Within the AP and TD framework, the speech motor planning processes described in linguistic models can be ascribed to the level of inter-gestural coupling graphs, inter-gestural planning oscillators and gestural score activation; while processes pertaining to speech motor programing would typically encompass dynamic gestural specifications at the level of tract variables and articulatory synergies ( Nam and Saltzman, 2003 ; Nam et al., 2009 ; Tilsen, 2009 ).

Traditionally, perceptual inconsistency in speech production of children with CAS has been evaluated via word-level token-to-token variability or at the fine-grained segmental-level (phonemic and phonetic variability; Iuzzini and Forrest, 2010 ; Iuzzini-Seigel et al., 2017 ). These studies provide evidence for increased variability in speech production of CAS relative to those typically developing or those with other speech impairments (e.g., articulation disorders). Data suggest that speech variability issues in CAS may arise at the level of articulatory synergies (intra-gestural coordination). Children with CAS demonstrate higher lip-jaw spatio-temporal variability with increasing utterance complexity (e.g., word length: mono-, bi-, and tri-syllabic) and greater lip aperture variability relative to children with speech delay ( Grigos et al., 2015 ). Terband et al. (2011) analyzed articulatory kinematic data on functional synergies in 6- to 9-year-old children with SSD, CAS, and typically developing controls. The results indicated that the tongue tip-jaw synergy was less stable in children with CAS compared to typically developing children, but the stability of lower lip-jaw synergy did not differ ( Terband et al., 2011 ). Interestingly, differences in movement amplitude emerged between the groups: CAS children exhibited a larger contribution of the lower lip to the oral closure compared to typically developing controls, while the children with SSD demonstrated larger amplitude of tongue tip movements relative to CAS and controls. Terband et al. (2011) suggest that children with CAS may have difficulties in the control of both lower lip and tongue tip while the children with SSD have difficulties controlling only the tongue tip. Larger movement amplitudes found in these groups may indicate an adaptive strategy to create relatively stable movement coordination (see also Namasivayam and van Lieshout, 2011 ; van Lieshout, 2017 ). The presence of larger movement amplitudes to increase stability in the speech motor system has been reported as a potential strategy in other speech disorders, including stuttering ( Namasivayam et al., 2009 ); adult verbal apraxia and aphasia ( van Lieshout et al., 2007 ); cerebral palsy ( Nip, 2017 ; Nip et al., 2017 ); and Speech-Motor Delay [SMD, a SSD subtype formerly referred to as Motor Speech Disorder–Not Otherwise Specified (MSD-NOS); Vick et al., 2014 ; Shriberg, 2017 ; Shriberg et al., 2019a , b ]. This fits well with the notion that movement amplitude is a factor in the stability of articulatory synergies as predicted in a DST framework (e.g., Haken et al., 1985 ; Peper and Beek, 1998 ) and evidenced in a recent study on speech production ( van Lieshout, 2017 ). Additional mechanisms to improve stability in movement coordination were documented in gestural intrusion error studies ( Goldstein et al., 2007 ; Pouplier, 2007 , 2008 ; Slis and van Lieshout, 2016a , b ) as discussed in section “Describing Casual Speech Alternations,” and are more present in adult apraxia speakers relative to healthy controls ( Pouplier and Hardcastle, 2005 ; Hagedorn et al., 2017 ).

With regards to the lengthened and disrupted coarticulatory transitions, findings suggest that abnormal and variable anticipatory coarticulation (assumed to reflect speech motor planning) may be specific to CAS and not a general characteristic of children with SSD ( Nijland et al., 2002 ; Maas and Mailend, 2017 ). The lengthened and disrupted coarticulatory transitions between sounds and syllables can be explained by possible limitations in inter-gestural overlap in children with CAS. A reduction in overlap of successive articulatory gestures (i.e., reduced coarticulation or coproduction) may result in the speech output becoming “segmentalized” (e.g., as seen in adult apraxic speakers; Liss and Weismer, 1992 ). Segmentalization gives the perception of “pulling apart” of successive gestures in the time domain and possibly adds to perceived stress and prosody difficulties in this population (e.g., Weismer et al., 1995 ). These may arise from delays in the activation of the following gesture and/or errors in gesture activation durations.

Inappropriate prosody (lexical and phrasal stress difficulties) in CAS is often characterized by listener perceptions of misplaced or equalized stress patterns across syllables. A potential source of this problem is that children with CAS may produce subtle and not consistently perceptible acoustic differences between stressed and unstressed syllables ( Shriberg et al., 1997 ; Munson et al., 2003 ). Children with CAS unlike typically developing children, do not shorten vowel duration in weaker stressed initial syllables as an adjustment to the metrical structure of the following syllable ( Nijland et al., 2003 ). Furthermore, syllable omissions have been particularly noted in CAS children who demonstrated inappropriate phrasal stress ( Velleman and Shriberg, 1999 ). These interactions between syllable/gestural units and rhythmic (stress and prosody) systems have been discussed earlier in the context of multi-frequency systems of coupled oscillators (e.g., Tilsen, 2009 ). We speculate that children with CAS may have difficulty with stability in coupling (i.e., experience weak or variable coupling) between stress and syllable level oscillators.

Speech-Motor Delay

Speech-Motor Delay (formerly MSD-NOS; Vick et al., 2014 ; Shriberg, 2017 ; Shriberg and Wren, 2019 ; Shriberg et al., 2019a , b ) is a subpopulation of children presenting with difficulties in speech motor control and coordination that is not consistent with features of CAS or Dysarthria ( Shriberg, 2017 ; Shriberg et al., 2019a , b ). Information on the nature, diagnosis, and intervention protocols for the SMD subpopulation is emerging ( Vick et al., 2014 ; Shriberg, 2017 ; Namasivayam et al., 2019 ). Current data suggests that this group is characterized by poor motor control (e.g., higher articulatory kinematic variability of upper lip, lower lip and jaw, larger upper lip displacements). Behaviorally, they produce errors such as fewer accurate phonemes, errors in vowel and syllable duration, errors in glide production, epenthesis errors, consonantal distortions, and less accurate lexical stress ( Vick et al., 2014 ; Shriberg, 2017 ; Namasivayam et al., 2019 ; Shriberg and Wren, 2019 ; Shriberg et al., 2019a , b ). As many of the precision and stability deficits in speech and prosody in SMD (e.g., consonant distortions, epenthesis, vowel duration differences and decreased accuracy of lexical stress) and adaptive strategies to increase speech motor stability (e.g., larger upper lip displacements; van Lieshout et al., 2004 ; Namasivayam and van Lieshout, 2011 ) overlap with CAS and other disorders discussed earlier, we will not reiterate possible explanations for these within the context of the AP model. SMD is considered a disorder of execution: a delay in the development of neuromotor precision-stability of speech motor control. Children with SMD are at increased risk for persistent SSDs ( Shriberg et al., 2011 , 2019a , b ; Shriberg, 2017 ).

Developmental Dysarthria

Dysarthria “is a collective name for a group of speech disorders resulting from disturbances in muscular control over the speech mechanism due to damage of the central or peripheral nervous system. It designates problems in oral communication due to paralysis, weakness, or incoordination of the speech musculature” ( Darley et al., 1969 , p. 246). Dysarthria may be present in children with cerebral palsy (CP) and may be characterized by reduced speaking rates, prolonged syllable durations, decreased vowel distinctiveness, sound distortions, reduced strength of articulatory contacts, voice abnormalities, prosodic disturbances (e.g., equal stress), reduced respiratory support or respiratory incoordination and poor intelligibility ( Pennington, 2012 ; Mabie and Shriberg, 2017 ; Nip et al., 2017 ). Speakers with CP consistently produce greater lip, jaw and tongue displacements in speech tasks relative to typically developing peers ( Ward et al., 2013 ; Nip, 2017 ; Nip et al., 2017 ). These increased displacements were argued to arise from either a reduced ability to grade force control (resulting in ballistic movements) or alternatively, can be interpreted as a strategy to increase proprioceptive feedback to stabilize speech movement coordination ( Namasivayam et al., 2009 ; Nip, 2017 ; Nip et al., 2017 ; van Lieshout, 2017 ). Further, children with CP demonstrate decreased spatial coupling between the upper and lower lips and reduced temporal coordination between the lips and between lower lip and jaw ( Nip, 2017 ) relative to typically developing peers. These measures of inter-articulator coordination were found to be significantly correlated with speech intelligibility ( Nip, 2017 ).

Within the AP model, the neuromotor characteristics of dysarthria such as disturbances in gesture magnitude or scaling issues (overshooting, undershooting), imprecise articulatory contacts (resulting in sound distortions), slowness (reduced speaking rate and prolonged durations), and coordination issues could be related to inaccurate gestural specifications of dynamical parameters (e.g., damping and stiffness), inaccurate gesture activation durations, imprecise constriction location and degree, and inter-gestural and intra-gestural (i.e., articulatory synergy level) timing issues ( Browman and Goldstein, 1990a ; van Lieshout, 2004 ; Fuchs et al., 2006 ). Inter-gestural and intra-gestural timing issues may characterize difficulties in coordinating the subsystems required for speech production (respiration, phonation and articulation) and difficulties in controlling the many degrees of freedom in a functional articulatory synergy, respectively ( Saltzman and Munhall, 1989 ; Browman and Goldstein, 1990b ; van Lieshout, 2004 ). Overall, dysarthric speech characteristics would encompass the following levels in the AP/TD framework: inter-gestural coordination, and dynamic specifications at the level of Tract Variables and Articulatory Synergies ( Table 1 ).

Clinical Relevance, Limitations and Future Directions

In this paper, we briefly reviewed some of the key concepts from the AP model ( Browman and Goldstein, 1992 ; Gafos and Goldstein, 2012 ). We explained how the development, maturation, and the combinatorial dynamics of articulatory gestures in this model can offer plausible explanations for speech sound errors found in children with SSDs. We find that many of these speech sound error patterns are in fact present in speech of typically developing children and more importantly, even in the speech of typical adult speakers, under certain circumstances. Based on our presentation of behavioral and articulatory kinematic data we propose that such speech sound errors in children with SSD may potentially arise as a consequence of the complex interaction between the dynamics of articulatory gestures, an immature speech motor system with limitations in speech motor skills and specific boundary conditions related to physical, physiological, and functional constraints. In fact, much of these speech sound errors themselves may reflect compensatory strategies (e.g., decreasing speech rate, increasing movement amplitude, bracing, intrusion gestures, cluster reductions, segment/gesture/syllable deletions, increasing lag between articulators) to provide more stability in the speech motor system as has been found in both typical and disordered speakers ( Fletcher, 1992 ; van Lieshout et al., 2004 ; Namasivayam and van Lieshout, 2011 ).

Based on the presented evidence, we speculate that in general children with SSDs may occupy the low end of the speech motor skill continuum similar to what has been argued for stuttering ( van Lieshout et al., 2004 ; Namasivayam and van Lieshout, 2011 ) and that the differences we notice in speech sound errors between the subtypes of SSD may in fact be differences in how these individuals develop strategies for coping with the challenges of being on the lower end of the speech motor skill continuum. This is a critical shift in thinking about the (distal and proximal) causes for speech sound errors in children with SSD (or in adults for that matter). Many of these children show similarities in their behavioral symptoms and perhaps the traditional notion of separating phonological from motor issues should be questioned (see also Maassen et al., 2010 ) and replaced with a broader understanding of how all levels involved in speech production are part of a complex system with processing stages that are highly integrated and coupled at different time scales (see also Tilsen, 2009 , 2017 ). The AP perspective and the associated DST principles provide a suitable basis for this kind of approach given its transparency between higher and lower levels of control through the concept of gestures.

Despite the uniqueness of the AP approach in offering new insights into the underlying mechanisms of speech sound errors in children, there are some limitations of using this approach. For example, the current versions of the AP model does not have an auditory feedback channel and is unable to account for any effects of auditory feedback perturbations. Further, although there are some recent attempts at describing the neural mechanisms underlying the components of the AP model (e.g., Tilsen, 2016 ) the model generally does not explicitly specify neural structures as some other models have done (e.g., DIVA model; Tourville and Guenther, 2011 ; for a detailed comparison between models of speech production see Parrell et al., 2019 ).

Critically, the theoretical concepts of gestures/synergies in speech production from this framework are yet to be taught widely in professional S-LP programs and related disciplines (see also van Lieshout, 2004 ). There are several reasons for this knowledge translation issue with the top ones being a lack of availability of accessible reviews and tutorials on this topic, limited empirical data on the nature of SSDs in children from an AP framework, and most importantly the absence of convenient, reliable and published practical methods to assess the status of gestures and synergies in speech production in a clinical setting. Although, some intervention approaches like the Prompts for Restructuring Oral Muscular Phonetic Targets approach (PROMPT; Hayden et al., 2010 ) and the Rapid Syllable Transitions Treatment program (ReST; Thomas et al., 2014 ) aim at addressing speech movement gestures and transitions between them, they lack empirical outcome data related to their impact at the level of gestures and articulatory synergies. It is also unclear at this point whether or not it is possible to provide tools to identify differences in timing relationships in jaw-lip or tongue tip-jaw coupling that would work well in a clinical setting. Using purely sensory (visual and auditory) means to observe speech behaviors will always be subject to errors and biases common to perception-based evaluation procedures (e.g., Kent, 1996 ). At the moment, there is a paucity of literature in this area which opens up great opportunities for future research. With technologies like real time Magnetic Resonance Imaging finding its way into the analysis of typical and disordered speech (e.g., see Hagedorn et al., 2017 ) and relatively low cost automatic video-based face-tracking systems ( Bandini et al., 2017 ) starting to emerge for clinical purposes, we hope that speech-language pathologists will have the tools they need to support their assessment and intervention planning based on a better understanding and quantification of the dynamics of speech gestures and articulatory synergies. To this end, we hope that this paper provides an initial step in this direction as an introduction to the AP framework for clinical audiences and a motivation for a larger cohort of researchers for developing testable hypothesis regarding the contribution of gestures and articulatory synergies to sub-types of SSD in children.

The foundations of clinical assessment, classification and intervention for children with SSD have been heavily influenced by psycholinguistics and auditory-perceptual based transcription procedures ( Shriberg, 2010 ; see Section Articulatory Phonology and Speech Sound Disorders in Children ). A major problem as noted earlier (in the Introduction section) is that, the complex relationships between the etiology (distal), processing deficits (proximal) and the behavioral levels (speech symptoms) is under-specified in current SSD classification systems ( Terband et al., 2019a ). It is critical to understand the complex interactions between these levels as they have implications for differential diagnosis and treatment planning ( Terband et al., 2019a ). There have been some theoretical attempts made toward understanding these interactions (e.g., Inkelas and Rose, 2007 ; McAllister Byun, 2012 ; McAllister Byun and Tessier, 2016 ), and we hope this paper will trigger a stronger interest in the field of S-LP for an alternative “gestural” perspective and increase the contributions to the limited corpus of research literature in this area.

Author Contributions

AN: main manuscript writing, synthesis and interpretation of literature, brain storming concepts and ideas, and creation of tables and figures. DC and AO: main manuscript writing, brain storming concepts and ideas, references, and proofing. PL: overall supervision of manuscript, writing subsections, and original conceptualization.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

1 The term “speech sound error” refers to a mismatch between what an individual intends to say and what they actually say ( Harley, 2006 ). In children, this may entail a clinically significant impairment or a non-standard production of speech sounds of the ambient language and may be classified according to the units of processing (e.g., phoneme, syllable, word or phrase) and the mechanisms (substitutions, additions, omissions/deletions and distortions) involved ( Harley, 2006 ; Preston et al., 2013 ). The word “sound” is included in the term “speech sound error” to distinguish it from other speech errors such as disfluencies, voice and language (e.g., grammatical errors) based errors ( McLeod and Baker, 2017 ).

2 There are also certain states that are inherently unstable, which are referred to as repellors.

3 For an alternative take on velar fronting using the Harmonic Grammar framework and AP model see McAllister Byun, 2011 , 2012 ; McAllister Byun and Tessier, 2016 .

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Articulation for Speech Therapy: How Does It Work?

One of the key areas speech therapists work on to improve both verbal and non-verbal communication is speech.

Speech is an aspect that deals with articulation, stutters, and voice disorders—elements that directly impact the way you speak.

Today, we’ll look at how articulation for speech therapy works.

We’ll tackle its importance, the building blocks necessary to develop it, the problems that can occur with poor articulation, and how to improve articulation.

What Is Articulation in Speech Therapy?

Articulation in speech therapy or articulation therapy focuses on pronunciation and talking .

It deals with a person’s ability to move the lips, tongue, teeth, and jaw to produce speech sounds.

Also called traditional articulation therapy, it supports and improves the formation of words and sounds.

It also determines how well you can be understood by those on the receiving end of your verbal information.

Why Is Articulation Important in Speech?

Articulation determines how well sounds, words, and sentences are produced and how clearly they can be interpreted by others.

Good articulation helps one engage in reciprocal conversations with ease and fluency.

Depending on the severity, speech difficulties can impact how well children interact with adults and their peers.

It affects how their language and social skills develop.

A child who cannot be understood easily can get angry and frustrated about their situation.

That, in turn, could lead to behavioral issues.

Literacy skills, such as reading and spelling, are also influenced by articulation.

Articulation for speech therapy works to address all these issues and more to improve a child’s verbal and non-verbal communication skills.

How to Develop Good Articulation

It doesn’t matter if your child meets their speech milestones on time or if they’re operating on their own timeline and are a bit late to the program.

What’s important is that they develop in the following aspects to have good articulation:

Having good hearing helps a child better detect speech sounds and model his or her sounds after them.

Of course, this would require the child’s everyday models to be good at articulating words and phrases.

Middle Ear Functioning

In most cases, problems with the middle ear are what affect speech.

Whether it’s ear infections, ear wax, or colds that block the ears, they usually have a way of interfering with a child’s hearing.

This, in turn, impacts the way words and sounds are articulated.

You can count on traditional articulation therapy to deal with these problems with efficacy.

Muscle Coordination

Muscle coordination is a huge factor in determining the quality of sounds that comes out of a person’s mouth.

The way the muscles in your diaphragm, tongue, vocal cords, palate, and jaw move and coordinate contribute to your articulation.

If you’re healthy in all these areas, that can go a long way to helping you produce great sounds.

Speech Sound Processing

This deals with how a child identifies even the slightest differences in sounds.

When mispronounced even the slightest, vowels can completely change what a word sounds like to a listener.

A speaker who processes speech well can understand sounds better and, in turn, create them correctly.

Understanding

Good articulation has a lot to do with how one understands sound.

When you know the meaning a specific sound conveys, you can stay true to that meaning when you create it.

Attention and Focus

Articulation may be easy when you get the hang of it, but it does take work to get it to a good place.

To become excellent in articulation, you need to be able to listen to and produce speech at a sustained level without getting affected by distractions.

It doesn’t necessarily need to be too long, either, but just enough to get the task of communicating done effectively.

Articulation speech therapy can help a child achieve just the right balance between these elements.

Signs of Articulation Problems

A child who finds it challenging to articulate usually shows the following signs:

• Frustration due to the inability to get the point across
• Produce sounds and words that are difficult to place even for friends and family
• Finds difficulty in combining two or more sounds
• Mostly uses vowel sounds, which are open-mouthed and easier to produce
• Produces messy speech while eating messily
• Produces speech that’s significantly less clear than his or her peers
• Has a lisp that causes mispronunciation of sibilants, like s and z, as a toddler or preschooler
• Finds it difficult to produce several sounds even by kindergarten

More Serious Problems Related to Articulation

Articulation difficulties can also lead to problems in the following areas:

Socializing

A child who doesn’t articulate clearly can have difficulty engaging in mutual interactions with other kids and adults.

They will find it hard to compromise with their peers and not be able to identify or follow norms.

Self-esteem

Poor articulation can be tough for kids.

With the teasing also comes the loss of confidence in themselves and their speaking skills.

This can result in a child staying mostly quiet and keeping to themselves.

They may no longer hold any kind of belief that they can accomplish a task.

Independence

The only way a child will feel safe is when he or she is at home or with a parent.

This is probably because of all the teasing in school due to his or her speech impediment.

Make sure you get in touch with the school or the teacher if you suspect this could be happening.

It can be incredibly frustrating for a child to not be understood when he or she wants to communicate so badly.

This happening constantly can manifest in your child’s behavioral changes.

You might find your little one becoming overly frustrated about his or her situation.

Reading and Spelling

Here’s another area that will take the brunt of poor articulation.

The sounds that come out of the child’s mouth will be difficult to understand and could lead to some embarrassing moments at school.

This is one more reason to have articulation speech therapy implemented urgently.

Using Expressive Language

When articulation is less than ideal, it can limit how a child is able to express themselves.

Expressive language relies on various forms of communicating wants, ideas, thoughts, and needs.

A child whose articulation isn’t quite at a high level may resort to shortening sentences or phrases to be understood better.

This deals with the flow of words, sounds, and syllables.

With poor articulation, you can hardly expect a child to achieve the peak of fluency in terms of verbal communication.

How Can I Help My Child With Speech Articulation Problems?

Pronunciation and talking problems in speech can be addressed using the following solutions:

If you have no idea what your little one is talking about, ask him or her to show you what it is instead.

You can also ask your child to repeat the word or sentence and try to guess what he or she means.

You shouldn’t be afraid to tell your child that you don’t understand.

Reading to your youngster can help overcome articulation problems.

Listening and Responding

Don’t pay too much attention to pronunciation errors.

Instead, try to understand your child’s message and respond to it.

Talking often to your little one helps them have a daily model for proper word pronunciation.

This serves as another opportunity for parents to model and use a variety of different sounds to help kids pronounce correctly.

Reducing Background Noise

Background noise can impede articulation development in some kids.

As such, when engaging with your youngster, make sure distractions are minimal, or there are none at all.

Maintain eye contact with your child when speaking to them.

Encourage them to not look away from you so that they can copy how sounds are created and how words are pronounced correctly.

Words and sentences that are unclear bear repeating.

Answer an unclear question by repeating it back to your child.

Doing so helps you become a good language model and shows your child that you were listening to what he or she was saying.

How Do You Fix Articulation in Speech Through Activities?

The following are activities that can help improve pronunciation and talking:

Naming the things your child sees daily is a great way to remedy articulation problems in speech.

Of course, you must make sure the words and sounds that come out of your mouth are correct.

In this way, your child has a good model for articulation.

Do facial expressions with your child in the mirror.

Show your little one how the lips, jaw, mouth, and tongue are supposed to be shaped when creating certain sounds.

Doing a variety of sounds during play and daily interactions let the child associate a specific sound with an action.

For instance, “shhh” would pertain to sleeping.

When a word is uttered incorrectly, make sure to model back the correct pronunciation.

There’s no need to tell your child they were wrong.

Respond through positive correction by shaping your response to model the correct version of the word, phrase, or sentence that was just said.

How Articulation for Speech Therapy Helps

Articulation therapy offers therapeutic intervention for children with talking and pronunciation issues.

It helps improve their ability to produce clear speech and sounds and understand other sounds.

It also aims to help them engage with others verbally and non-verbally, spell and read, as well as deal with speech problems and challenges.

Five Common Speech Disorders in Children

You have determined that your child has more than just a speech delay, now what? How do you determine what kind of speech disorder your child has and more importantly, what do you do about it? We have listed below five common speech disorders in children. Of course, we always recommend a visit to your pediatrician if you feel your child has any of these symptoms, and an appointment with an SLP may be necessary to begin an effective speech therapy treatment plan.

5 Common Speech Disorders in Children:

Articulation Disorder: An articulation disorder is a speech sound disorder in which a child has difficulty making certain sounds correctly.  Sounds may be omitted or improperly altered during the course of speech. A child may substitute sounds (“wabbit” instead of “rabbit”) or add sounds improperly to words. Young children will typically display articulation issues as they learn to speak, but they are expected to “grow out of it” by a certain age.  If the errors persist past a standard developmental age, which varies based on the sound, then that child has an articulation disorder.

The most common articulation disorders are in the form of a “lisp” – when a child does not pronounce the S sound correctly – or when a child cannot pronounce the R sound correctly. He may say “wabbit” instead of “rabbit” or “buhd” or instead of “bird.”

Apraxia of Speech is a communication disorder affecting the motor programming system for speech production.  Speech production is difficult – specifically with sequencing and forming sounds. The person may know what he wants to say, but there is a disruption in the part of the brain that sends the signal to the muscle for the movement necessary to produce the sound.  That leads to problems with articulation as well as intonation and speaking stress and rhythm errors. Apraxia of Speech can be discovered in childhood (CAS), or might be acquired (AOS) resulting from a brain injury or illness in both children and adults.

Fragile X Syndrome (FXS) is an inherited genetic disorder that is the most common cause of inherited intellectual disabilities in boys as well as  autism  (about 30% of children with FXS will have autism). It also affects girls, though their symptoms tend to be milder. It is greatly under-recognized and second only to  Down syndrome  in causing intellectual impairment.

FXS occurs when there is a mutation of FMRI gene and is an inherited disorder.  If a child received a pre-mutated X chromosome from one of his parents (as a carrier), then he is at greater risk of developing FXS.  Diagnosing Fragile X Syndrome is not easy for parents and doctors at the beginning of a child’s life.  Few outward signs are noticeable within the first 9 months. These signs may include an elongated face and protruding eyes.

Intellectual disabilities, speech and language problems, and social anxiety occur most frequently in children with Fragile X. Speech symptoms include repetition of words and phrases, cluttered speech and difficulties with the pragmatics of speech. All of FXS’s symptoms can range from mild to very severe.

Stuttering occurs when speech is disrupted by involuntary repetitions, prolonging of sounds and hesitation or pausing before speech. Stuttering can be developmental, meaning it begins during early speech acquisition, or acquired due to brain trauma. No one knows the exact causes of stuttering in a child.  It is considered to have a genetic basis, but the direct link has not yet been found. Children with relatives who stutter are 3 times as likely to develop stuttering. Stuttering is also more typical in children who have congenital disorders like  cerebral palsy .

A child who stutters is typically not struggling with the actual production of the sounds—stress and a nervousness trigger many cases of stuttering. Stuttering is variable, meaning if the speaker does not feel anxious when speaking, the stuttering may not affect their speech.

Language disorders can be classified in three different ways: Expressive Language Disorder (ELD), Receptive Language Disorder (RLD) or Expressive-Receptive Language Disorder (ERLD).  Children with Expressive Language Disorder do not have problems producing sounds or words, but have an inability to retrieve the right words and formulate proper sentences. Children with Receptive Language Disorder have difficulties comprehending spoken and written language. Finally, children with Expressive-Receptive Language Disorder will exhibit both kinds of symptoms. Grammar is a hard concept for them to understand and they may not use of articles (a, the), prepositions (of, with) and plurals. An early symptom is delay in the early stages of language, so if your child takes longer to formulate words or starting to babble, it can be a sign of ELD.

Children with Receptive Language Disorder may act like they are ignoring you or just repeat words that you say; this is known as “echolalia.” Even when repeating the words you say, they may not understand.  An example of this is if you say, “Do you want to go to the park?” and they respond with the exact phrase and do not answer the question. They may not understand you or the fact that you asked them to do something.

Children with Expressive-Receptive Language Disorder can have a mix of these symptoms

These are some of the most common speech disorders in children. No child is the same and you know your child best. If you feel that your child has a speech disorder, contact your pediatrician to discuss treatment options.

The Kid’s Speech: When Pronunciation Problems Persist

By Jessica Minier Mabe

Published on: september 25, 2013.

Getting the right treatment to help children speak clearly can help a young child academically and socially. But what about older kids who still struggle to pronounce the sounds correctly?

Older kids with speech problems often have trouble with lisps or with creating the sounds made by the letters th, r or l, says Wendy Bell, a speech and language pathologist at Seattle Children’s Hospital . Other kids might speak in a voice that’s too high, raspy or with “too much nasality,” she says.

Most parents notice these problems early on and seek treatment. This can be critical, since not all speech clarity issues improve on their own. Nine-year-old Jacob Bright’s mother, Jenny Bright of Bellevue, first noticed Jacob’s speech issues when he was 16 months old. Her pediatrician referred the Brights to early intervention therapies. Today, though Jacob’s speech has improved, he is still receiving speech therapy through the Bellevue School District .

Neicole Crepeau, Kirkland mother of Conrad (18) and Devon (14), also first noticed her children’s speech issues when they were very young. “Conrad had something of a lisp and didn’t pronounce his r’s clearly. Devon tended to slur his words, like he was talking too fast,” she says.

Some speech clarity issues are caused by physical problems, as was the case for Conrad. When he received braces and medical devices to move his jaw, his mother remembers, “The orthodontist told us it might improve his speech, and as it turned out, it did.”

But for Devon, practicing to speak more slowly has helped him improve his speech clarity. Crepeau and her husband worked with him at home, reminding him to slow down.

“We also devised sentences that had the sounds that he tended to slur and we had him try to say them clearly several times a day,” she says. Today, Devon’s speech is better. “If he gets tired, he gets lazy and slurs. But he seems to be more careful himself to try to speak clearly.”

Getting help

How can parents decide whether to call in the professionals to help their child’s speech? First, talk to your child’s pediatrician — he or she can refer you to a speech therapist if necessary. Treatments vary, depending upon the diagnosis.

Bell explains that while speech therapy may be all that is needed for a lisp, it might be necessary to check for “tongue thrust.” The resting position of the tongue can be important for developing the motions needed to correctly produce s and z sounds, says Bell.

But some speech issues don’t resolve as early as we’d like them to. Many kids still have trouble pronouncing certain sounds through the higher grade school years and into middle school. That’s when the social scene ramps up — and when kids who can’t pronounce their r’s or still have a lisp, for example, often get embarrassed. Some of the kids may even be bullied.

According to a Penn State University study, kids with speech issues experience a higher rate of bullying than other kids, particularly “relational bullying,” which means they get left out or publicly humiliated. Increasingly, speech and language pathologists are being trained to work with these children in the hope of reducing bullying, by using problem solving and role playing and encouraging children to speak up, according to the Penn State  study .

Parents can also step in. At Jacob’s ninth birthday party, one of his friends asked Jenny Bright why he “spoke funny.”

“I told the boy that I had speech delays as a child and Jake inherited some of those from me. I also told him that as a friend of Jake, we should look out for each other, and if someone says something mean, to tell the teacher — or tell that person to knock it off.”

Crepeau feels her son Devon was actually motivated to improve his speech after encountering some teasing from peers. “Devon started practicing on his own … he took an interest in working on it because of those jokes from his friends.”

If you think your child’s speech is generating social problems for your child, ask yourself these questions, says Bell. “How does your child feel about the speech or communication difference? Is it getting worse? Have others commented negatively or expressed sincere concern?”

If your child is feeling embarrassed or awkward, or others have started to point out speech differences, speech therapy may be the best way to restore a child’s confidence. “Speech and vocal quality hold strong characteristics for identification and personality,” Bell says. “I’m a strong advocate for getting kids the services they need.”

Jessica Minier Mabe is a private tutor and writer. Her work is featured on her award-winning blog . She lives with her partner and their three children.

American Speech-Language-Hearing Association This website provides general information about speech clarity issues for all ages, as well as providing a database of speech therapy providers.

Seattle Children’s Speech and Language Program

Myofunctional Clinic of Bellevue Myofunctional treatment may help with some of the physical causes of speech clarity issues.

Seattle Public Schools’ information on IEPs This Web page provides a walk-through of the individual education plan process for Seattle school district students, including resources for parents with children in private schools.

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About the author.

Jessica Minier Mabe has been a high school and middle school English teacher for 15 years, as well as a trip planner, private tutor and writer. Her work is featured on her award-winning blog , where she publishes essays, movie reviews, stories and poems, as well as photographs and craft projects. She lives with her partner, Joe, and her son, Henry.

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Dysarthria occurs when the muscles you use for speech are weak or you have difficulty controlling them. Dysarthria often causes slurred or slow speech that can be difficult to understand.

Common causes of dysarthria include nervous system disorders and conditions that cause facial paralysis or tongue or throat muscle weakness. Certain medications also can cause dysarthria.

Treating the underlying cause of your dysarthria may improve your speech. You may also need speech therapy. For dysarthria caused by prescription medications, changing or discontinuing the medications may help.

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Signs and symptoms of dysarthria vary, depending on the underlying cause and the type of dysarthria. They may include:

• Slurred speech
• Slow speech
• Inability to speak louder than a whisper or speaking too loudly
• Rapid speech that is difficult to understand
• Nasal, raspy or strained voice
• Uneven or abnormal speech rhythm
• Uneven speech volume
• Monotone speech
• Difficulty moving your tongue or facial muscles

When to see a doctor

Dysarthria can be a sign of a serious condition. See your doctor if you have sudden or unexplained changes in your ability to speak.

In dysarthria, you may have difficulty moving the muscles in your mouth, face or upper respiratory system that control speech. Conditions that may lead to dysarthria include:

• Amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease)
• Brain injury
• Brain tumor
• Cerebral palsy
• Guillain-Barre syndrome
• Head injury
• Huntington's disease
• Lyme disease
• Multiple sclerosis
• Muscular dystrophy
• Myasthenia gravis
• Parkinson's disease
• Wilson's disease

Some medications, such as certain sedatives and seizure drugs, also can cause dysarthria.

Complications

Because of the communication problems dysarthria causes, complications can include:

• Social difficulty. Communication problems may affect your relationships with family and friends and make social situations challenging.
• Depression. In some people, dysarthria may lead to social isolation and depression.
• Daroff RB, et al., eds. Bradley's Neurology in Clinical Practice. 7th ed. Elsevier; 2016. https://www.clinicalkey.com. Accessed April 10, 2020.
• Dysarthria. American Speech-Language-Hearing Association. https://www.asha.org/public/speech/disorders/dysarthria/. Accessed April 6, 2020.
• Maitin IB, et al., eds. Current Diagnosis & Treatment: Physical Medicine & Rehabilitation. McGraw-Hill Education; 2020. https://accessmedicine.mhmedical.com. Accessed April 10, 2020.
• Dysarthria in adults. American Speech-Language-Hearing Association. https://www.asha.org/PRPPrintTemplate.aspx?folderid=8589943481. Accessed April 6, 2020.
• Drugs that cause dysarthria. IBM Micromedex. https://www.micromedexsolutions.com. Accessed April 10, 2020.
• Lirani-Silva C, et al. Dysarthria and quality of life in neurologically healthy elderly and patients with Parkinson's disease. CoDAS. 2015; doi:10.1590/2317-1782/20152014083.
• Signs and symptoms of untreated Lyme disease. Centers for Disease Control and Prevention. https://www.cdc.gov/lyme/signs_symptoms/index.html. Accessed April 6, 2020.
• Neurological diagnostic tests and procedures fact sheet. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Neurological-Diagnostic-Tests-and-Procedures-Fact. Accessed April 6, 2020.

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The Top 5 Pronunciation Problems and How to Fix Them

1. Stressing individual words incorrectly If you usually speak with native English speakers, this will be the number one reason why they misunderstand you. It’s very hard for native English speakers to ‘translate’ a word spoken as ‘caLENdar’ to the way they would pronounce it, ‘CALendar’.

Non-native English speakers don’t have as much of a problem with this, and will probably still understand what you’re trying to say.

Quick fix: Listen carefully to the way people around you pronounce their words. If you hear a pronunciation that is different from yours, check the dictionary (even if it’s a common word) to be sure that you’re stressing it correctly. Some commonly mis-stressed words that I hear (with proper stress in capitals) include: PURchase, COLleague, phoTOGraphy and ecoNOMic. You will also find a number of commonly mispronounced words listed in the ‘How to Pronounce…’ section of this blog.

2. Stressing the wrong words in a sentence. Remember that you can completely change the meaning of a sentence by stressing different words in that sentence. For example, you could say this sentence in a number of different ways:

“I didn’t say we should drive this way.”

If you stress I , you emphasize that taking that route wasn’t your idea. On the other hand, if you stress drive , you emphasize the mode of transport.

If you don’t pay close attention to the words that you stress, you could end up sending a completely different message than the one you intended.

Quick fix: Think about placing added emphasis on the word that is most important to your meaning. You can add emphasis by lengthening the word, saying it slightly louder and/or changing the pitch of your voice slightly. Listen to Part 8 of the Pronunciation Short Course for further discussion.

3. Pronouncing certain consonant sounds incorrectly If people are misunderstanding you, it could very well be due to you confusing what we call ‘voiced’ and ‘unvoiced’ sounds. You might substitute ‘p’ for ‘b’ or ‘t’ for ‘d’, for example. These sounds are so easily confused because their only difference is whether or not you use your voice to produce them. If you aren’t careful, you could be making mistakes like saying ‘tuck’ for ‘duck’ or ‘pay’ for ‘bay’.

Quick fix: Pay attention to how you use your voice when you speak. You should be able to feel the vibration of your vocal cords when you make voiced sounds (b, d, g, v, z, r, l, m, n, ng, dge, zh, and voiced th). You can also try to make lists of pairs of words that use the sounds you find challenging and practice repeating those. Record yourself so you can hear whether you’re making any progress.

4. Mixing up short and long vowel sounds Vowel sounds , like consonant sounds, can also be confused easily. The main problem with vowels happens when you mix up long and short vowel sounds. For example, the long ‘ee’ sound in ‘seat’ with the short ‘i’ sound in ‘sit.’ If you confuse these sounds, you end up saying completely different words. This can get confusing in conversation and forces people to draw much more from the context of your speech than the speech itself.

Quick fix: Make practice word lists like the ones you made for the consonant sounds and practice the sounds that are difficult for you.

5. Forgetting to finish your words Do you have a tendency to let your word endings drop? I often hear people drop the ‘ed’ ending off of words in the past tense, for example. This is a dangerous mistake because not only is your pronunciation wrong, but it also sounds like you’re making a grammatical mistake. People could judge you based on this type of error.

Quick fix: Do everything you can to articulate your word endings. One exercise that might help is to move the word ending onto the front of the following word. This will only work if the following word begins with a vowel sound. For example, try saying ‘talk tuh lot’ instead of ‘talked a lot’.  Check out Part 5 of the FREE, 8-part Pronunciation Short Course at http://bit.ly/free8-partproncourse  for more information on linking.

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Reader Interactions

March 15, 2011 at 12:25 am

Spot on Heather! If we paid more attention to to the last stop in our communication process, we’d have a lot more clarity and confidence in our representation of the ideas that we’re getting across to other people. I especially like your point (3) about ‘voiced’ and ‘unvoiced’ sounds! I had a ball going through the letters! Oooh … I also like your blog – I’ve been meaning to do one up as well. Perhaps I can ‘bribe’ you with lunch and you bring along your laptop and show me how? 🙂

March 16, 2011 at 1:17 am

Hey Ricky! Thanks for your comments! Glad you enjoyed the voiced and unvoiced sounds! I’ll get back to you over email regarding lunch. 😉

August 10, 2012 at 9:59 pm

This is a great summary of the important points that foreign speakers get stuck on. I am a TESOL graduate student specialising in L2 pronunciation, it’s an emotionally charged issue in addition to be a difficult part of language learning. I see so many students beat themselves up over their pronunciation problems. Thank you for sharing this information.

September 1, 2012 at 2:11 pm

So many people mispronounce Australia. You should have a sixty second guide on how to pronounce Australia.

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How Early Memory Loss Shows Up in Everyday Speech

Conversational cues may arise sooner than other signs of mental decline.

If your memory seems OK but your speech is slipping – you can find the car keys but not always your words – should you be concerned? Possibly so, according to a new study. Among a group of adults in late middle age who were functioning fine in their day-to-day lives, those whose conversational patterns declined most during a two-year period were more likely to develop mild cognitive impairment .

[See: 5 Ways to Cope With Mild Cognitive Impairment .]

It's perfectly normal to use fillers like "um" and "ah" in your speech, says Kimberly Mueller , an associate researcher at the University of Wisconsin–Madison and lead author of the study presented in July at the Alzheimer's Association International Conference in London. It would take a much more marked deterioration in fluency and syntax to possibly foreshadow a progressive loss of memory and eventual dementia .

Having a word on the tip of your tongue is a common experience . However, when retrieving words takes longer and longer, or someone can't retrieve words at all, that's significant. Repeating sounds and filling pauses with "um" more and more frequently as time passes is another telling sign.

"It does become harder to retrieve words in normal aging," says Mueller, who is a speech-language pathologist . "But the problems we see in mild cognitive impairment and dementia are so severe that they happen multiple times, even in one or two sentences. And often the message is just lost and [people] can't get their thoughts across."

Participants for the study had previously enrolled in the Wisconsin Registry for Alzheimer's Prevention. Launched in 2001, WRAP is believed to be the largest long-term study of healthy people who have a family member with Alzheimer's disease , putting them at higher risk of developing dementia themselves.

An unexpected finding in the new study, which included 264 at-risk adults from the larger WRAP group, was that participants found to have early MCI performed higher on syntax at the study's start. That was analyzed from a one-minute speech sample after they were asked to describe a simple picture.

However, at the repeat speech analysis done at the two-and-a-third year mark, their speech had declined more steeply than for those adults with stable cognitive health. That drop in language ability correlated with development of early mild cognitive impairment in 64 participants, based on up to 10 years of follow-up testing.

Identifying these conversational cues at home might be important for getting people to seek help sooner. "If it is noticeable and interfering with socializing or with getting needs met, then it would be worth going to your doctor and talking about that," Mueller says. That could prompt further screening for cognitive impairment, she adds, as well as a discussion among health care providers, patients and families.

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Jessica Leigh Zwerling, M.D. Aug. 16, 2016

Recording snippets of conversation during regular doctor's visits could potentially serve as a new type of screening tool to pick up mental changes sooner than current methods, Mueller says. Speech comparisons and analysis done from one visit to the next might provide a quick, simple and inexpensive measure of cognitive ability over time.

[See: Easy Ways to Protect Your Aging Brain .]

Once dementia is diagnosed and has progressed, speech deterioration becomes more obvious. Different types of dementia cause different speech problems, says Dr. Ken Brummel-Smith , a professor emeritus with the department of geriatrics in the Florida State University College of Medicine. With Alzheimer's, he says, speech-related issues usually don't occur until the middle stages.

Conversational problems tied to memory loss often show up before actual language changes. People "often make things up, and especially if they're very social, they have pretty ingenious ways of getting around the fact that they don't remember something," Brummel-Smith says.

He recalls working with a patient and trying to perform a mental status test. Whenever the patient was asked who the current U.S. president was, a standard test item, she would say, "They're all crooks; I don't pay attention to that anymore," to cover her memory lapses.

In terms of language, Brummel-Smith says, "Usually, the first change in Alzheimer's-type dementia is anomia: difficulty remembering words. The next thing is [people] start saying words incorrectly."

In this stage, known as paraphasia, if an evaluator held up a wristwatch, for example, someone with dementia might respond with "clutch," combining the words watch and clock . "They'll often try different sounds until they hear something that sounds right," Brummel-Smith explains.

Neologisms – made-up words that are completely indecipherable – mark the nadir of language decline. Unfortunately, Brummel-Smith says, a person at this stage may only be able to say one or two words, frequently cry out, moan or make guttural sounds.

With a less-common type of dementia called primary progressive aphasia, language problems start before memory problems arise. People can still function intellectually at this point, Brummel-Smith says. He recalls a case of a lawyer who could still write fluently but had difficulty speaking and others had to take on his court-related trial work. Eventually, he progressed to dementia.

Whatever the type of dementia, Brummel-Smith says, language deterioration is similar in final stages.

[See: How Music Helps Patients With Alzheimer's Disease .]

Some family members and caregivers instinctively "get" how to talk to people struggling with dementia. Others might benefit most from interventions to improve their communication, for instance by working with a speech-language pathologist.

Helpful strategies include using simple sentences, bringing instructions down to single steps rather than multistep commands and, when appropriate, accompanying spoken language with a gesture, like pointing to your eyes when talking about them.

On the other hand, making comments like "I told you 100 times" is counterproductive after someone asks the same question over and over, Brummel-Smith says. "They don't remember being told the first time," he points out. Scolding born of frustration just raises their levels of anxiety and anger.

Accepting that loved ones have a brain disorder that doesn't allow them to do what they used to do is key, according to Brummel-Smith. "They can't change," he says. "They don't have the brain power to make a change. But we can always change for them."

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Poilievre wades into Middle East conflict during speech to Montreal-area synagogue

Blames oct. 7 attacks on iran, says conservatives would 'defund antisemitism'.

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It can be one of the thorniest issues for Canadian politicians — highly divisive and filled with decades of fighting, with potential for political blowback from one side or the other.

While conflict has raged in the Middle East in recent months, federal Conservative Leader Pierre Poilievre has tended to focus on bread-and-butter domestic issues, such as inflation and the Liberal government's carbon tax.

In the House of Commons, Poilievre has referred to Israel or Gaza only a handful of times.

However, during a speech at a Montreal-area synagogue last week, Poilievre provided one of the most comprehensive glimpses since becoming Conservative leader of his relationship with Israel, his views on the conflict in the Middle East and the history of the Jewish people.

His speech at Beth Israel Beth Aaron Congregation — an Orthodox synagogue in Côte Saint-Luc, Que. — also potentially foreshadows the approach a Poilievre government would take on issues such as the Middle East, which he described as a difficult question, and antisemitism.

Officials from Poilievre's office have not yet responded to requests from CBC News for comment.

• Hamas determined to maximize Israeli and Palestinian deaths, Poilievre says

The synagogue is located in Liberal MP Anthony Housefather's riding of Mount Royal. Housefather, a longtime Liberal who is Jewish, is currently reflecting on his future in the party after most of his fellow caucus members voted on March 18 in favour of a controversial but non-binding NDP motion to work toward the recognition of the State of Palestine as part of a negotiated two-state solution.

Conservatives, three Liberals, including Housefather, and independent MP Kevin Vuong voted against the motion.

Speech gets standing ovation

At the March 26 event at the Quebec synagogue, Poilievre was introduced as the "next prime minister of Canada." A video of the event that was shot by a member of the audience, who allowed CBC News to view it, shows Poilievre's 33-minute speech peppered by applause and standing ovations. Conservative MP Melissa Lantsman, the party's deputy leader, later posted video of the speech to YouTube.

The event provided a showcase for Poilievre's knowledge of Jewish religion and culture. He recounted the story of Purim, where the Jewish people refused to relinquish their religion, and sprinkled his speech with familiar expressions, referring to himself as "a simple goy from the Prairies."

Poilievre recounted his hitchhiking trip to Israel in his youth and the impressions it left on him — such as participating in a Shabbat in Betar and hearing songs being sung in Hebrew.

"The Jewish people are the only people I know of who, in the same language, worship the same faith on the same land in the same country as they did 3,000 years ago. That is a true indigenous people," Poilievre said to applause and cheers.

Israelis and Palestinians both maintain that they are indigenous to the area.

• 'Remember who we are': Trudeau calls for calm as tensions rise over Israel-Hamas war
• Gaza's Al-Shifa Hospital in ruins after Israeli troops withdraw

Poilievre talked about staying in a kibbutz near Ein Gedi, a historic site and nature reserve located near Masada and the Dead Sea — then standing in the Golan Heights in the north, watching missiles being fired from Lebanon.

"We literally witnessed with our own eyes Hezbollah lobbing missiles into northern Israel and the courageous IDF forces flying back into south Lebanon to retaliate against the attack," he said.

The Canadian government does not recognize permanent Israeli control over the Golan Heights.

Poilievre said when he returned to Canada, he helped launch "a full-scale campaign to criminalize Hezbollah."

Palestinians 'a chess piece in an evil chess game'

As he has done in recent months, Poilievre blamed the Oct. 7 attacks in Israel on Iran, saying it has been occupying Gaza through its intermediary, Hamas, and wanted to prevent peace accords.

About 1,200 people were killed in the Hamas-led attacks on southern Israel and about 250 people were taken hostage, according to Israeli tallies. More than 32,000 Palestinians in Gaza have been killed during Israel's military response since then, health officials in the territory say.

"It was the fear that discord would come to an end and that hope would take root that most terrified the regime in Iran," Poilievre told the audience. "And so, they orchestrated the attack. The Hamas leaders travelled to Tehran. They got funding and weapons from Tehran and ultimately co-ordination."

Poilievre says Hamas is 'determined to maximize' death and suffering

"I'm sorry, but I refuse to believe that rag-tag terrorists in Gaza were able to accumulate all of those weapons and all of that intelligence and co-ordination on their own," the Conservative leader said to applause. "This was an outside job."

Poilievre repeated his past call for Canada to ban Iran's Islamic Revolutionary Guard Corps, saying it was responsible for the downing in 2020 of a Ukraine International Airlines plane that killed 55 Canadian citizens and 30 Canadian permanent residents.

"This group operates legally on Canadian territory," he said. "It can recruit, co-ordinate, mobilize, fundraise legally on Canadian soil over three years after they murdered 55 of our citizens."

Poilievre said his heart goes out to the families of dispossessed Palestinians, saying the "Palestinian people have been made by the Iranian regime and other dictators in the regime, in the region, into a chess piece in an evil chess game."

"I understand why the political pressures are high, and I understand why our Muslim friends and neighbours are suffering and are legitimately speaking out for the suffering of their loved ones in Gaza and in the West Bank."

Poilievre told the audience he says the same things in mosques as he does in synagogues: "I love meeting with the Muslim people. They are wonderful people. When the issue of Israel comes up, I say, 'I'm going to be honest with you. I am a friend of the State of Israel, and I will be a friend of the State of Israel everywhere I go.'"

Poilievre wants UN relief agency to be defunded

Poilievre accused Prime Minister Justin Trudeau of delivering different messages to different groups for political gain.

"He sends one group into synagogues to say one thing, and then he sends another group of MPs into mosques to say precisely the opposite."

Poilievre said he believes in a negotiated two-state solution, with Palestinians and Israel living in peace and harmony. He said a Conservative government would stand up for Israel's right to defend itself and would reject any motions or resolutions at the United Nations that it believes unfairly target Israel.

The Canadian government should defund the United Nations Relief and Works Agency for Palestinian Refugees in the Near East (UNRWA) and ensure that "Canadian aid actually goes to the suffering Palestinian people and not to those promoting terrorism in UNRWA," he said.

"We, as a rule, around the world, common-sense Conservatives under my leadership will be cutting back foreign aid to terrorist dictators and multinational bureaucracies and using the money to rebuild the Canadian Armed Forces."

• Canada confirms it will resume funding United Nations relief agency for Palestinians

Poilievre pledged to "remove the bureaucracy and streamline the funding" for the federal government program that funds security infrastructure for places of worship and to "defund antisemitism."

"We will go line by line through all the groups that get dollars from the federal government, and we will defund every single one of those that promote antisemitism in our country."

We don't know what the world will bring tomorrow. But a thousand years from now, when the sun goes down on Fridays, millions of Jews around the world will observe Shabbat. <br><br>Thank you to the Beth Israel Beth Aaron Congregation of Côte Saint-Luc for welcoming me last night. <br><br>Am… <a href="https://t.co/45E6Djf3Cc">pic.twitter.com/45E6Djf3Cc</a> &mdash; @PierrePoilievre

Poilievre recalled a trip he made to Auschwitz, a concentration and extermination camp primarily for Jews that was run by Nazi Germany in Poland during the Second World War, and said it left him in tears. In April 2009, when he was parliamentary secretary to then-prime minister Stephen Harper, Poilievre attended the Conference Against Racism, Discrimination and Persecution in Geneva, and also visited Auschwitz and Birkenau to commemorate the victims of the Holocaust.

He praised the resilience of the Jewish people.

"I don't know what the world will bring tomorrow. I don't know, much less 100 years from now. But I do know this, that a thousand years from now, whatever is going on, on Fridays, as the sun goes down, there will be a Shabbat in Israel," Poilievre said to a standing ovation. "Those songs will be sung. The Jewish people will go on."

ABOUT THE AUTHOR

Senior reporter

Award-winning reporter Elizabeth Thompson covers Parliament Hill. A veteran of the Montreal Gazette, Sun Media and iPolitics, she currently works with the CBC's Ottawa bureau, specializing in investigative reporting and data journalism. She can be reached at: [email protected].

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Jamie Dimon Issues an Economic Warning

The JPMorgan Chase chief executive used his annual letter to shareholders to flag higher-for-longer inflation, uncertain growth prospects and widening political divisions.

By Andrew Ross Sorkin ,  Ravi Mattu ,  Bernhard Warner ,  Sarah Kessler ,  Michael J. de la Merced ,  Lauren Hirsch and Ephrat Livni

Jamie Dimon sees America at a ‘Pivotal Moment’

Jamie Dimon’s annual letter to JPMorgan Chase shareholders has just been published. The widely read note offers a glimpse of his views on not just business, but the economy at a “pivotal moment for America and the free world,” with deep divisions at home and global uncertainty.

Here are some highlights.

The economy is resilient but the government underpinning it is a red flag. Consumers are spending and investors expect a soft landing. But Dimon warns that the economy is being fueled by government spending and rising deficits. “The deficits today are even larger and occurring in boom times — not as the result of a recession — and they have been supported by quantitative easing, which was never done before the great financial crisis,” he writes.

Inflation may be sticky. “These markets seem to be pricing in at a 70% to 80% chance of a soft landing — modest growth along with declining inflation and interest rates,” Dimon writes, adding that the odds are actually a lot lower.

Global uncertainty is another dark cloud. The wars in Ukraine and the Middle East could further “disrupt energy and food markets, migration, and military and economic relationships.” That shock coincides with a surge in public investment to power a green transition, restructure supply chains and trade relationships, and boost health care spending.

Industrial policy is needed but should be limited and targeted. Dimon says the U.S. must be tough with China, but engage with Beijing. That includes establishing independence on supplies of materials crucial to national security, like rare earth, semiconductors and 5G infrastructure. (According to Dimon, the Inflation Reduction Act and the CHIPs Act get it right.)

Dimon warns about the deep political divisions at home. Dimon doesn’t explicitly weigh in on the election (his public backing for some of Donald Trump ’s economic policies caused a stir at Davos in January), but said the U.S. is grappling with “highly charged, emotional and political” issues centering around the border security crisis and the “fraying of the American dream.”

On Basel 3 endgame: Dimon reiterated his concerns that many of the proposed banking rules are “flawed and poorly calibrated.”

On corporate governance: Dimon argues that proxy advisory firms like ISS have become too influential (he recently backed Disney in its fight against Nelson Peltz). He is opposed to recent efforts to split chairman and C.E.O. roles and thinks the universal proxy “makes it easier to put poorly qualified directors on a board.”

HERE’S WHAT’S HAPPENING

Janet Yellen sees progress in China relations, but warns there’s “more work to do.” The Treasury secretary concluded meetings in Beijing on Monday saying that ties between the nations had stabilized, but it was unclear how the relationship would endure in an election year. Her comments came as the Biden administration agreed to give Taiwanese chipmaker TSMC $6.6 billion in grants to begin manufacturing in Arizona in 2028.

Brazil’s supreme court opens an investigation into Elon Musk. Alexandre de Moraes, the chief justice, opened the instruction of justice inquiry after Musk said he would reactivate some X accounts that the judge had ordered blocked. The accounts weren’t disclosed. Moraes has been investigating “digital militias” accused of spreading disinformation.

Gold hits a record high and an oil rally takes a breather. The safe-haven asset reached more than $2,300 a troy ounce , buoyed by worries over a widening conflict in the Middle East and higher demand for the precious metal from central banks and Chinese consumers. The price of Brent crude fell on Monday to trade near $90 a barrel, down from a five-month high reached last week.

Is it show time for Warner Bros. Discovery?

Today marks the two-year anniversary of the Warner Bros. Discovery mega deal closing. Crossing that milestone means that the entertainment giant, which owns HBO, CNN and a lucrative piece of the March Madness broadcasts, can now strike a deal without facing a huge tax hit.

The industry is ripe for consolidation , given challenges in cable and streaming. An obstacle is President Biden’s antitrust cops. “Regulatory constraints are limiting what deals can get done, which is the case in most industries,” Rob Kindler, the global chair of the M.&A. Group at Paul, Weiss, told DealBook.

Warner Bros. Discovery hasn’t gone as hoped. Its stock is down 66 percent since the deal closed as its bet on streaming has languished (alongside rivals not named Netflix). The legacy cable business has been a bigger drag, hurt by cord-cutting.

Its $44 billion debt mountain could also make an acquisition more difficult. But John Malone, the media mogul and a board member, said in November that cash flow is improving, which could set the company up to scout for deals.

A merger with Paramount seems unlikely. Shares fell 5 percent when talks between the two leaked in December, a sign that investors may not look enthusiastically on the company increasing its exposure to linear media. It’s probably a moot point anyhow with Paramount in exclusive talks with Skydance .

Even still, would an alliance with Paramount’s TV networks, like, CNN and CBS through a spinoff or divestiture make sense, down the line?

Targeting Comcast could face challenges, too. Investors may like the potential to combine their cable, studio and streaming businesses. But regulators would likely have tough questions.

Still, don’t count out a deal. As Barry Diller told The Times last year : There seems to always be interest in the Warner media properties. “Whether that will happen depends on whether someone wants to take it,” said Diller, a longtime friend of the Warner Bros. Discovery chief, David Zaslav.

Rethinking the deals-are-bad trope

For decades, the common wisdom in corporate America — as encapsulated in the 2004 book “Mastering the Merger,” by two Bain & Company consultants — was that for all the billions spent on mergers, roughly 70 percent failed.

But a new white paper by one of the book’s authors and two other colleagues finds that the inverse is now true: 70 percent of takeovers succeed . DealBook got the first look at the research to learn what had changed.

Companies have gotten smarter about M.&A. In 2004, the defining deals of the era — including that of AOL-Time Warner — were meant to be transformative and deliver big savings. Today the goals are more modest, such as expanding into new geographies or adjacent businesses, or adding new talent.

Acquirers are also getting more practice. Having more-conservative aims for mergers means companies can do more of them, justifying having in-house teams of M.&A. specialists who can better identify promising acquisitions and make them work. One advancement: more sophisticated analysis of potential takeovers, compared with earlier deals that often relied on less exacting financial considerations like synergies.

“Frequent acquirers have the experience and capability to do the diligence that’s required,” Suzanne Kumar, a Bain vice president and one of the white paper’s authors, told DealBook, pointing to Thermo Fisher Scientific, Constellation Brands and tech giants.

Serial acquirers tend to have better returns. Between 2000 and 2010, companies that did at least one deal a year had 10-year total shareholder returns that were 57 percent higher than businesses that did no deals, Bain found. Between 2012 and 2022, that spread rose to 130 percent — a finding that surprised the researchers.

Unionization efforts come to Harvard Yard

With car companies on high alert over the United Auto Workers’ efforts to ramp up labor organizing, the union has racked up a series of wins far from the factory floor — on college campuses.

The most recent victory was at Harvard University. The school’s nontenure track employees — a group of roughly 6,000 that includes faculty, postdoctorate fellows and preceptors — overwhelmingly voted to unionize last week. That opens the door to negotiations for higher wages, improved job security and bolstering workplace protection.

The divide brings another source of tension to campus. Harvard has been embroiled in a fight over free speech and safety ever since Hamas attacked Israel on Oct. 7, spurring a debate that led to a wave of high-level resignations.

Harvard is far from alone. Staff at Wellesley College and New York University also voted to unionize this year, joining efforts by adjunct professors and postdocs at Boston University, Columbia, Rutgers and the University of Connecticut.

The U.A.W. is at the center of the push. The union has been branching into higher education for years. And its hard-knuckled tactics in securing new contracts from Detroit’s Big Three automakers last year have given it momentum.

After N.Y.U.’s successful unionization vote, Shawn Fain, the U.A.W.’s president, hailed the moment as a historic one for labor organizing efforts on America’s university campuses. “We’ve got their back,” he said .

The week ahead

Congress returns today from its two-week recess to find Ukraine, the TikTok bill and repairing the Baltimore bridge in the spotlight — and a possible House leadership challenge looming. Elsewhere, inflation, central banks and the new earnings season will also be in focus.

Here’s what to watch:

Tuesday: Google’s Cloud Next developers conference opens amid expectations that the tech giant will make a raft of announcements to do with artificial intelligence.

Wednesday: The March Consumer Price Index is set for release. Economists forecast that overall inflation rose by 3.5 percent on an annualized basis, a slight increase from February. Core C.P.I., which removes food and fuel, is expected to have cooled.

Minutes from the last Fed meeting are also due to be published.

Elsewhere, President Biden will hold talks at the White House with Prime Minister Fumio Kishida of Japan. On the agenda : trade, A.I. and China. Also looming over the summit is Nippon Steel’s $14 billion bid for U.S. Steel.

Thursday: It’s decision day on rates for the European Central Bank. Inflation has fallen relatively quickly across much of Europe, prompting the question: Will the E.C.B. cut interest rates before the Fed?

Friday: Wall Street giants begin reporting first-quarter results, including JPMorgan Chase, Wells Fargo, Citigroup and BlackRock.

THE SPEED READ

The luxury group Puig, owner of the brands Paco Rabanne and Charlotte Tilbury, plans to list in Spain and aims to raise more than 2.5 billion euros ($2.7 billion) in what would be the sector’s biggest I.P.O. in years. (FT)

Could investors’ relative apathy for European stocks push the continent’s biggest oil companies to consider bigger listings in the U.S. ? (Bloomberg Opinion)

Josh Shapiro, the Democratic governor of Pennsylvania, has warned that the Biden administration’s decision to pause liquefied natural gas projects could hurt the party’s chances in November. (FT)

“ Maryland Passes 2 Major Privacy Bills , Despite Tech Industry Pushback” (NYT)

Best of the rest

Solar eclipse mania has gripped North America, and there’s good news : The weather should cooperate for a decent viewing across big parts of the U.S. (NYT)

South Carolina has topped Caitlin Clark and Iowa to win the women’s national basketball championship. Up tonight: UConn takes on Purdue — and there’s a Bill Murray connection . (The Athletic, WSJ)

We’d like your feedback! Please email thoughts and suggestions to [email protected] .

Andrew Ross Sorkin is a columnist and the founder and editor at large of DealBook. He is a co-anchor of CNBC’s "Squawk Box" and the author of “Too Big to Fail.” He is also a co-creator of the Showtime drama series "Billions." More about Andrew Ross Sorkin

Ravi Mattu is the managing editor of DealBook, based in London. He joined The New York Times in 2022 from the Financial Times, where he held a number of senior roles in Hong Kong and London. More about Ravi Mattu

Bernhard Warner is a senior editor for DealBook, a newsletter from The Times, covering business trends, the economy and the markets. More about Bernhard Warner

Sarah Kessler is an editor for the DealBook newsletter and writes features on business and how workplaces are changing. More about Sarah Kessler

Michael de la Merced joined The Times as a reporter in 2006, covering Wall Street and finance. Among his main coverage areas are mergers and acquisitions, bankruptcies and the private equity industry. More about Michael J. de la Merced

Lauren Hirsch joined The Times from CNBC in 2020, covering deals and the biggest stories on Wall Street. More about Lauren Hirsch

Ephrat Livni reports from Washington on the intersection of business and policy for DealBook. Previously, she was a senior reporter at Quartz, covering law and politics, and has practiced law in the public and private sectors.   More about Ephrat Livni