Speech Sound Disorders and Related Anatomy

SSD Overview and Classification

• Definition of Speech Sound Disorders (SSD):

  • Childhood onset, not injury-related

  • Not due to dialect or accent

  • Considered a problem by the child or by the community

• Related terms and classification (Speech Disorders Classification System: A Clinical Typology Based on Etiology):

  • Speech Delay (SD)

  • Speech Sound Disorders (SSD)

  • Speech Errors (SE)

  • Motor Speech Disorder (MSD)

• Subtypes and etiologies mentioned:

  • Genetic factors

  • Otitis Media with Effusion (OME)

  • Psycho-social factors

  • Apraxia (MSD)

  • Dysarthria NOS (not otherwise specified)

• Example patterns referenced: /s/ and /r/ sound issues (illustrative speech error patterns)

Anatomy and Brain for Speech Production

• Five processing steps in speech production:

  • Respiratory

  • Phonatory

  • Resonatory

  • Articulatory

  • Auditory

• Central and Peripheral Nervous System involvement:

  • CNS = brain + spinal cord

  • PNS = cranial nerves + spinal nerves

• Lateralization of functions:

  • Left hemisphere predominantly for speech and language

  • Right hemisphere predominantly for prosody and music

Key Brain Areas

• Primary Motor Cortex (precentral gyrus)

• Broca’s Area (usually left hemisphere) in the Frontal Lobe

• Primary Auditory Cortex

• Wernicke’s Area (usually left hemisphere) in the Temporal Lobe

• Parietal Lobe (general processing and integration)

• Occipital Lobe (visual processing, not primary for speech, but referenced in broader context)

• Basal Ganglia

• Thalamus

• Cerebellum

• Brainstem

Respiratory System and Phonation

• Respiratory system provides the power for speech:

  • Inspiration driven by the diaphragm and external intercostals

  • Expiration driven by internal intercostals and abdominal muscles

• Phonation (speech production):

  • Biological function: airway protection

  • Speech function: vocal fold vibration

  • Mechanisms: Bernoulli effect contributing to vocal fold adduction/abduction

• Vocal Fold Dynamics:

  • Vibration for voicing

  • Adduction/Abduction control the onset and maintenance of voicing

Resonance and Vocal Tract Anatomy

• Resonance occurs in: pharyngeal, oral, and nasal cavities

• Velopharyngeal closure controls nasal vs oral resonance (important for normal resonance)

• Major anatomical regions (survey):

  • Nasal Cavity, Paranasal sinuses

  • Oral Cavity, Pharynx (nasopharynx, oropharynx, hypopharynx)

  • Salivary Glands

  • Glottis and Vocal Cords within the Larynx

  • Epiglottis, Trachea, Subglottis

• Velopharyngeal mechanism is essential for nasal passage control during speech

Articulators

• Movable articulators: tongue, lips, jaw, velum (soft palate), larynx

• Immovable structures: palate (hard palate), alveolar ridge, teeth

• Key articulatory components listed in the figure: Epiglottis, Hyoid bone, Thyrohyoid membrane, Thyroid cartilage, Cricoid cartilage, Arytenoid cartilage, Trachea

Phonetics Review: Anatomy of the Speech Sound System

• Palatal and dentition landmarks referenced: Gingiva (gums), Hard palate, Uvula, Papillae of tongue, Premolars, Molars

• Lip and oral structures: Lips, Soft palate (velum), Palatine tonsil

IPA and Transcription

• IPA as a universal phonetic system; English spelling does not map 1:1 to sounds

• Examples of phonetic vs phonemic transcription:

  • Phonetic transcription uses square brackets [ ] to capture exact pronunciation in a given instance (e.g., [tʰ] for aspirated /t/ as in "top")

  • Phonemic transcription uses slashes / / to denote the underlying sound category (e.g., /t/ representing the /t/ sound in "top" and in stops in general, regardless of aspiration)

• Notation basics:

  • [tʰ] denotes aspiration of the /t/ sound

  • /t/ denotes the mental category of the /t/ sound

Phonetic Principles

• A solid working knowledge of IPA is necessary to:

  • Accurately capture speech production

  • Identify speech errors

  • Understand speech errors for treatment planning

• Transcription prerequisites:

  • Before phonetic transcription, count the number of sounds in words correctly

  • Focus on sounds heard rather than letters seen in writing

Phonetic Practice and Key Terms

• Word-level practice (example items from the slide):

  • Mine, Catch, One, Two, Three, Touched, Think, Jumping

• Grapheme, Phoneme, Allophone:

  • Grapheme = a letter

  • Phoneme = a meaningful sound category (mental representation)

  • Allophone = a phonetic variation of a phoneme with no meaning change

Phoneme Classification: Sonorants vs Obstruents

• Sonorants: airflows with open or relatively unobstructed pathways

• Obstruents: involves obstructed airflow

• This primary distinction informs place/mrequency and perception of consonant groups

Types of Sonorants

• Vowels

  • Nucleus of the syllable

• Nasals

• Liquids

• Glides

Vowels: Description and Features

• Front vowels: tongue position toward the front of the mouth

  • /i/ as in "beat" (high front unrounded)

  • /ɪ/ as in "bit" (near-high front lax)

  • /e/ as in "bait" (mid front)

  • /ε/ (often written as /ɛ/) as in "bet"

  • /æ/ as in "bat" (low front)

• Back vowels: tongue positioned toward the back of the oral cavity

  • /u/ as in "boot" (high back)

  • /ʊ/ as in "book" (near-high back)

  • /ɔ/ as in "ought" (mid back, open-mid)

  • /ɑ/ as in "father" (low back)

• Central vowels / mid central vowel: /ɝ/ (stressed "bird"), /ə/ (schwa as in "about"), /ɚ/ (unstressed schwar), /ʌ/ (as in "bud")

• Monophthongs vs Diphthongs:

  • Monophthong: one vowel sound that does not move during articulation

  • Diphthong: starts with one vowel and moves to another within a single syllable

  • Components: On-glide (beginning) and Off-glide (ending)

Diphthongs and R-Colored Vowels

• Common examples and representations in teaching slides:

  • Diphthong examples shown conceptually with words such as Hive, Hoist, Yikes, Cows, Shy

• R-colored vowels (rhotic vowels):

  • Air = /ɛər/ or /er/

  • Fear = /ɪər/

  • Corn = /ɔːr/

  • Tour = /ʊər/ or /ɔɚ/

  • Car = /ɑr/

  • Additional rhotic diphthongs include patterns like /ɚ/ and /ɝ/ in American English

Nasals and Liquids

• Nasals: sounds produced with resonance in the nasal cavity

  • /m, n, ŋ/

• Liquids: produced by shaping air through the oral cavity

  • /l, r/

Glides

• Glides must glide into a following vowel

  • Sounds: /j, w/

• Classification: Sonorants with open airflow

• vowels, nasals, liquids

• Characteristics: Glides function as the onset of a syllable and are produced with a quick transition, lacking a constriction that would classify them as stops or fricatives.

Obstruents: Stops, Fricatives, and Affricates

• Three types of obstruents:

  • Stop: air is stopped and then quickly released

  • Examples: /p/, /b/, /t/, /d/, /k/, /g/

  • Fricative: air is forced through a small constriction, causing friction

  • Examples: /f/, /v/, /s/, /z/, /ʃ/, /ʒ/, /θ/, /ð/, /h/

  • Affricate: begins as a stop, ends as a fricative

  • Examples: /tʃ/, /dʒ/

Consonants: Place, Manner, and Voicing

• Place of Articulation (examples):

  • Bilabial, Labiodental, Interdental, Alveolar, Alveolo-palatal, Palatal, Velar, Glottal

• Manner of Articulation (examples):

  • Stops, Nasals, Glides, Fricatives, Affricates, Liquids

• Voicing distinctions accompany most consonants (e.g., /p/ vs /b/, /t/ vs /d/, etc.)

• Representative consonant inventory often summarized as:

  • Stops: /p, b, t, d, k, g/

  • Fricatives: /f, v, s, z, ʃ, ʒ, θ, ð, h/

  • Affricates: /tʃ, dʒ/

  • Nasals: /m, n, ŋ/

  • Liquids: /l, r/

  • Glides: /w, j/

Summary of Key Concepts for Exam Preparation

• SSD vs SD vs SE vs MSD distinctions and etiologies (genetic, OME, psycho-social)

• Brain and speech localization: left hemisphere language centers (Broca’s and Wernicke’s), right-hemisphere prosody

• Five speech production processes and their neural substrates

• Respiratory-phonatory coupling and the physics of phonation (Bernoulli effect, adduction/abduction of vocal folds)

• Resonance and velopharyngeal closure for nasal/oral balance

• Articulator mobility: mobile vs immobile structures; key laryngeal and supraglottal components

• Phonetic vs phonemic transcription; IPA usage; aspiration notation ([tʰ]) vs underlying phoneme (/t/)

• Grapheme-Phoneme-Allophone distinctions and their relevance to transcription and error analysis

• Sonorants vs Obstruents; four types of sonorants; three obstruent types

• Vowels: tongue position, lip rounding, nucleus concept, rhotic vowels; monophthongs vs diphthongs; on-glide vs off-glide

• Diphthongs and rhotic vowels with common examples

• Nasals, Liquids, and Glides as part of the sonorant group

• Obstruent categories with examples and place/manner/voicing framework

• Consonant inventory by place, manner, and voicing to guide assessment and treatment planning

Quick Reference: Key Symbols and Terms (LaTeX-formatted where appropriate)

• Five speech production processes: $5$ processes: Respiratory, Phonatory, Resonatory, Articulatory, Auditory

• Stop consonants: $p, b, t, d, k, g$

• Fricatives: $f, v, s, z, ʃ, ʒ, θ, ð, h$

• Affricates: $tʃ, dʒ$

• Nasals: $m, n, ŋ$

• Liquids: $l, r$

• Glides: $w, j$

• Vowels: front: $i, ɪ, e, ε, æ$; back: $u, ʊ, ɔ, ɑ$; rhotics: $ɝ, ɚ, ɛər, ɪər, ɔr, ɑr$

• Diphthongs: start-vowel + end-vowel transitions (on-glide/off-glide)

• Phonetic transcription: [ ] for phonetic detail; Phonemic transcription: / / for underlying categories

• Grapheme: letter; Phoneme: mental sound category; Allophone: variant without meaning change