APA Dictionary of Psychology

in DSM–IV–TR, a communication disorder characterized by failure to develop and consistently use speech sounds that are appropriate for the child’s age. It most commonly involves misarticulation of the later acquired speech sounds, such as [l], [r], [s], [z], [ch], [sh], or [th] (see lalling; lisp), but it may also include substitution of sounds (e.g., [t] for [k]) or omission of sounds (e.g., final consonants). These problems are not due to, or are in excess of those normally associated with, hearing loss, structural deficits in the mechanism of speech production (e.g., cleft palate), or a neurological disorder. In DSM–5 and DSM-5-TR, phonological disorder is termed speech sound disorder. Formerly called developmental articulation disorder.