Perception of formant transition cues to place of articulation in children with language impairments.

Discrimination and phonetic identification abilities of 5- to 6-year-old children with language impairments were compared to those of 4-year-olds with normally developing language and to previous findings from 5- to 6-year-olds and adults for synthetic stimuli ranging from [ba] to [da]. Results showed similar discrimination sensitivity to the second- and third-formant transition cues of stimuli by all children, with poorest sensitivity by the youngest. Phonetic categorization by children with language impairments was most different from the groups with normal language abilities, evidenced by a difference in the percent of tokens labeled as "BA" and by greater variability in labeling and in placement of phonetic category boundaries. Results support hypotheses by Gathercole and Baddeley (1990) suggesting that the phonological component of working memory may be disordered in children with language impairments. Results are also suggestive of specific difficulties with left-hemisphere processing associated with language learning rather than with problems related to sensitivity to formant transitions of the speech tokens.