3. Speech Sound Disorders

Phoneme

A speech sound category that can change a word's meaning, such as /p/ and /b/ in pat and bat.

International Phonetic Alphabet (IPA)

A system of symbols used to represent speech sounds.

Are letters and sounds the same?

No. English spelling is inconsistent; sh represents one sound, and c can represent different sounds.

Consonants

Speech sounds produced with some constriction of airflow.

Vowels

Speech sounds produced with a relatively open vocal tract.

Three consonant parameters

Place of production, manner of production, and voicing.

Place of production

Where a speech sound is produced in the vocal tract.

Manner of production

How airflow is restricted or shaped when producing a sound.

Voicing

Whether the vocal folds vibrate during a speech sound.

Bilabial sounds

Sounds made with both lips, such as /p/, /b/, and /m/.

Labiodental sounds

Sounds made with the upper teeth and lower lip, such as /f/ and /v/.

Interdental sounds

Sounds made with the tongue between the teeth, such as /θ/ in think and /ð/ in this.

Alveolar sounds

Sounds made near the alveolar ridge, such as /t/, /d/, /s/, /z/, /n/, and /l/.

Palatal/postalveolar sounds

Sounds made near or just behind the hard palate or alveolar ridge, such as /ʃ/ in sh, /tʃ/ in ch, and /dʒ/ in j.

Velar sounds

Sounds made with the back of the tongue near the soft palate, such as /k/, /g/, and /ŋ/ in ng.

Glottal sounds

Sounds produced at the vocal folds, such as /h/ and a glottal stop.

Stop consonants

Sounds made by completely closing airflow and then releasing it, such as /p/, /b/, /t/, /d/, /k/, and /g/.

Fricatives

Sounds made by forcing air through a narrow opening, creating friction, such as /f/, /v/, /s/, /z/, and /ʃ/.

Affricates

Sounds that begin as stops and release into fricatives, such as /tʃ/ in ch and /dʒ/ in j.

Nasals

Sounds produced with airflow through the nose, such as /m/, /n/, and /ŋ/.

Liquids

Sounds made with relatively open airflow and tongue shaping, such as /l/ and /r/.

Glides

Sounds involving smooth movement into a vowel-like sound, such as /w/ and /j/ (the y sound).

Voiced sounds

Sounds produced with vocal fold vibration, such as /b/, /d/, /g/, /v/, and /z/.

Voiceless sounds

Sounds produced without vocal fold vibration, such as /p/, /t/, /k/, /f/, and /s/.

Describe /p/ by place, manner, and voicing

Bilabial, stop, voiceless.

Describe /g/ by place, manner, and voicing

Velar, stop, voiced.

Four vowel parameters

Tongue height, tongue advancement, roundness, and tension.

Tongue height

Whether a vowel is high, mid, or low.

Tongue advancement

Whether the tongue is positioned toward the front, center, or back of the mouth.

Vowel roundness

Whether the lips are rounded or unrounded.

Vowel tension

Whether a vowel is tense or lax.

Typical speech sound acquisition

Stops, nasals, and glides generally develop before many fricatives, affricates, and liquids.

Anterior versus posterior sound development

Anterior sounds generally develop before posterior sounds.

Consonant cluster development

Word-final clusters generally develop before word-initial clusters, and stop clusters generally develop before fricative clusters.

Speech sound disorder (SSD)

A significant difficulty producing speech sounds or using a language's sound system compared with developmental and cultural expectations.

What should be considered when identifying an SSD?

The child's age, developmental norms, and whether the difference is a disorder rather than a dialect, accent, or cultural variation.

Functional SSD

An SSD without an identifiable structural, sensory, or neurological cause.

Organic SSD

An SSD caused by an identifiable structural, sensory, or neurological condition.

Articulation impairment

Difficulty physically producing specific speech sounds.

Substitution speech error

Replacing one sound with another, such as wabbit for rabbit.

Omission speech error

Leaving out a sound, such as saying bi for bicycle.

Distortion speech error

Producing a sound inaccurately, such as a slushy or lateral /s/.

Phonological impairment

Difficulty understanding or applying the sound patterns and rules of a language.

Articulation versus phonological impairment

Articulation involves difficulty producing individual sounds; phonological impairment involves difficulty with sound patterns or rules.

Unstressed syllable deletion

Leaving out a weak syllable, such as telephone becoming tephone.

Final consonant deletion

Leaving off the final consonant, such as cat becoming ca.

Fronting

Replacing a sound made toward the back of the mouth with one made toward the front, such as key becoming tea.

Cluster reduction

Leaving out part of a consonant cluster, such as stop becoming top.

Stopping

Replacing a fricative with a stop, such as sun becoming tun.

Reduplication

Repeating a syllable, such as bottle becoming baba.

Consonant harmony

Changing one consonant to become more like another consonant in the same word, such as doggie becoming doddie.

Cleft lip

An opening in the upper lip.

Cleft palate

An opening in the roof of the mouth.

When should the lip and gum ridge close during development?

Around week 7.

When should the hard palate, soft palate, and uvula close during development?

Around weeks 10–12.

Cleft lip and palate effects

Possible feeding difficulties, dental problems, psychosocial challenges, ear infections, hearing loss, and speech and language disorders.

Why can cleft palate affect speech?

It can allow air to escape into the nasal cavity, making high-pressure consonants difficult to produce.

High-pressure consonants

Stops, fricatives, and affricates.

Compensatory speech errors associated with cleft palate

Some children may use glottal stops or pharyngeal fricatives instead of oral consonants.

Dental malocclusion

Misalignment of the teeth or jaws that may affect speech sounds.

Sensory impairment and speech

Hearing loss can reduce access to speech sounds and affect accurate speech development.

Somatosensation

Information about touch, position, and movement that helps a person sense and control their body.

Dysarthria

A motor speech disorder involving weakness or impaired control of muscles used for speech.

Apraxia of speech

A motor speech disorder involving difficulty planning and coordinating speech movements without muscle weakness or paralysis being the defining problem.

Articulation treatment

Practicing accurate target sounds, progressing from individual sounds to words, sentences, and conversation.

Phonological treatment

Targeting sound error patterns through methods such as minimal pairs and contrastive word practice.

Goldman-Fristoe Test of Articulation

A standardized test used to assess speech sound production.

Speech sound assessment methods

Case history, caregiver interviews or questionnaires, hearing screening, oral mechanism screening, language evaluation, standardized tests, and speech samples.

Treatment for organic SSDs

May involve interdisciplinary care, medical or surgical management, hearing support, or specialized motor speech treatment.