Speech Sound Disorders - In Depth Notes

Learning Objectives

  • Understand the process of speech production
  • Identify various speech disorders
  • Learn the types of speech disorders
  • Explore assessment methods for speech disorders
  • Review intervention strategies for speech disorders

What is Speech?

  • Speech is the production of sound through the coordination of various speech organs.

Human Body and Speech Production

  • Vocal Folds: Key in sound production.
  • Larynx: Acts as a voice box; important for producing sound.
  • Trachea: Passage for air, contributes to sound.

Speech Production Process

  • Involves careful planning, coordination, and movement of:
  • Jaw
  • Lips
  • Teeth
  • Tongue
  • Palate
  • Cheeks
  • Vocal cords (voice box)
  • Intelligibility: The ability to produce clear and understandable speech.

Properties of Speech Sounds

  1. Placement (Where?): The specific location in the mouth where sound is formed (e.g., lips, tongue).
  2. Manner (How?): The way in which airflow is shaped or restricted (e.g., stopping, flowing).
  3. Voicing/Devoicing: Whether vocal cords vibrate during sound production (+voiced or -voiceless).

Speech Disorders

  • Affect clarity and understandability of speech.
  • Arise from issues in:
  • Planning and Processing (brain struggles)
  • Movement (improper muscle function)

Types of Speech Sound Disorders

  1. Phonological Disorders: Issues in organizing speech sounds into patterns (cognitive aspect).
  2. Articulation Disorders: Problems with the physical production of sounds due to motor control issues.

Articulation Errors (SODA Method)

  1. Substitution: Replacing one sound with another. (e.g., "wed" for "red".)
  2. Omission: Leaving out a sound in a word. (e.g., "nake" for "snake".)
  3. Distortion: Producing a sound inaccurately. (e.g., "aks" for "ask".)
  4. Addition: Inserting an extra sound into a word. (e.g., "buhlack horse" for "black horse".)

Assessment Points

  1. Age of the child
  2. Condition of the articulators
  3. Speech intelligibility
  4. Child’s speech sound repertoire
  5. Impact of speech difficulties on child and family

Speech Sound Development Norms

  • Age 2: Initial /b/, /d/, /h/, /m/, /n/, /p/
  • Age 3: Additional sounds include /f/, /g/, /k/, /t/, /w/
  • Age 4: Introduction of consonant clusters

Speech Intelligibility Expectations

  • 19-24 Months: 25% to 50% intelligible speech
  • 2-3 Years: 50% to 75% intelligibility
  • 4-5 Years: 75% to 90% intelligibility
  • 5+ Years: 90% to 100%;
  • A few articulation errors may remain.

Screening and Diagnosis of Speech Disorders

  • Methods:
  • Parent reports
  • Structured/unstructured observations
  • Direct Assessment: To diagnose using both criterion-referenced and norm-referenced tools (e.g., DEAP, NZAT).

Intervention Strategies for Speech Sound Disorders

  • Traditional Articulation Therapy (TAT) should include a progressive sequence:
  1. Individual sounds
  2. Syllables
  3. Words
  4. Phrases
  5. Sentences
  6. Stories
  7. Conversations

References

  • Bowen, C. (2023). Children's speech sound disorders.
  • Ishmael, D. H. E. M. B. A. (2025). Challenges faced by learners with speech disorders.
  • McLeod S. & Baker E. (2016) Children's Speech: An Evidence-Based Approach to Assessment and Intervention.