Speech Sound Disorders

Organic speech sound disorders include those resulting from motor/neurological disorders (e.g., childhood apraxia of speech and dysarthria), structural abnormalities and sensory/perceptual disorders.

Functional speech sound disorders include those related to the motor production of speech sounds and those related to the linguistic aspects of speech production. Historically, these disorders are referred to as articulation disorders and phonological disorders, respectively. Articulation disorders focus on errors (e.g., distortions and substitutions) in production of individual speech sounds. Phonological disorders focus on predictable, rule-based errors (e.g., fronting, stopping, and final consonant deletion) that affect more than one sound. It is often difficult to cleanly differentiate between articulation and phonological disorders; therefore, many researchers and clinicians prefer to use the broader term, “speech sound disorder,” when referring to speech errors of unknown cause. See Bernthal, Bankson, and Flipsen (2017) and Peña-Brooks and Hegde (2015) for relevant discussions.