Speech perception development in language-impaired children: a 4-year follow-up study.

A group of specifically language-impaired (SLI) children was compared with a matched group of non-SLI children (i.e., children displaying normal language) on tests of speech perception and language ability. The tests were administered longitudinally at times separated by an interval of 4 years. Initially (i.e., Time 1), the groups differed significantly in discrimination, sequencing, and rate processing of and serial memory for synthesized /ba/ and /da/ stimuli. At Time 1, age effects were also observed among both groups of children. That is, performance improved as a function of increased age. At follow-up (i.e., Time 2), performance was at or near ceiling for subjects in both groups, indicating that perceptual development occurred in both groups of children. Results are discussed in relation to the hypothesis that perceptual deficits play a causal role in specific language impairment.