Unit VI: Speech Sound Disorders

Developmental disorder: a disorder prevalent in the early stages of human development with no clear cause



Congenital disorders: a disorder present at birth



Acquired disorder: a disorder caused by an event causing the impairment or loss of ability to articulate speech sounds



What is a Speech Sound Disorder:

  • Incorrect or imprecise articulation of words

    • Adults

    • Children when persisting later than typically-developing peers

  • Types:

    • Structural

    • Neuromotor

    • Phonological



Structural causes:

  • Structural damage or abnormality of the articulators

  • Cleft palate

    • Failure of the lip and/or the palate to fuse during fetal development

    • A congenital condition

  • Makes it difficult or impossible to speak typically

    • Cleft lip: problems with labial sounds

    • Cleft palate: hypernasality, incomplete constriction of the oral cavity

  • Can be repaired surgically, but speech sound disorder may be present



Neuromotor causes:

  • Impaired nervous system control of the muscles

    • Dysarthria: muscles are weak and paralyzed, lack coordination, or a combination of the two

    • Apraxia: problems with planning how to move the muscles



Dysarthria:

  • Several types with distinct features

  • Common features:

    • Imprecise articulation

    • Speech is slow and effortful

    • Disorders of voice and respiration are common

  • Causes:

    • Congenital: cerebral palsy

    • Acquired: stroke, Parkinson’s disease, amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease)



Apraxia of Speech:

  • No muscular weakness or paralysis present

  • Features:

    • Imprecise articulation

    • Speech is slow and effortful

    • May struggle with the articulators (“articulatory groping”)

    • Spastic breathing

    • Can’t make specific sounds (ma ma ma)

    • Disorders of voice and respiration are not common

  • Causes:

    • Developmental disorder in children

    • Acquired disorders in adults



Phonological disorders:

  • Movement of articulators are accurate, but speaker is producing the wrong sounds

  • Speech rate and rhythm are normal

  • No problems with voice or respiration

  • Causes:

    • Developmental disorder associated with language delays or difficulty learning to read

    • Acquired disorder



Two Types of Speech Error Patterns:

  • Articulation

  • Phonological process



Type of Error

Sentence

Type

Substitution

I tee the wabbit.

Typical development (before school-age) or phonological speech sound disorder (school age and older)

Omission

Boo → book

Ge → get

Nana → banana

Distortion


Structural and neuromotor speech sound disorders

Addition

Galass → glass



Common Phonological Errors:



Types of Deletion:




Phonological Process

Adult Word

Child Word

Simplification of Syllables

Final consonant deletion

bat

“ba-”

Unstressed syllable deletion

above

“-bove”

Cluster deletion

sleep

“-tep”

Assimilation

Regressive (backward) assimilation

dig

“gig”

Progressive (forward) assimilation

toad

“toat”

Substitution

Stopping–stop sounds are substituted for fricatives

sheep

“teep”

Fronting–alveolar sounds are substituted for palatal and velar sounds

came

“tame”



Assessment of Speech Sound Disorders in Children:

  • Assessment: Identification of the child’s needs and strengths

    • Hearing test

    • Oral mechanism evaluation: structure and function

    • Articulation inventory & Phonological processes



Intervention Methods:

  1. Acquisition: learning to produce the sound

    1. Minimal pairs: communicative difference

      1. Can vs pan

      2. Sea vs tea

    2. Visual cues

    3. Tactile cues

  2. Generalization: using the sound in new contexts

    1. In other contexts: → can vs back

    2. Longer utterances: words → phrases → sentences

    3. In other context: therapy → class activities

    4. With other people: clinician → parents, peers, strangers