Nature of phonological delay in children with specific language impairment

This study investigated the nature of phonological delay in a group of chil dren with specific language impairment. It was asked whether phonological e rrors in this group of children were generated by a slow but normal languag e learning process or whether they reflected a selective impairment in some representations that enhance normal acquisition and use of a language phon ology. A group of 10 children with SLI (mean age=5,1) was compared with thr ee groups of normal children who were matched in age (age control group, me an age = 5,1), in sentence comprehension and recalling (grammar control gro up, mean age = 3,7), or who exhibited a phonological performance lower than the age average (group with low phonological performance, mean age=4,4). T he four groups of children were assessed in terms of: (1) responses to a mi spronunciation detection task; and (2) error profiles with complex and simp le syllabic structures. Performance on the mispronunciation detection task showed that the group with SLI could distinguish a target lexical item from acoustic non-word stimuli that were highly similar to it in terms of phone tic characteristics. An analysis of overall error rate at this task showed, however, that four children with SLI had a much lower performance than nor mal children of the same age, even when the auditory stimuli were tokens of the target word, or non-words that were phonetically different from the ta rget. A difficulty in coordinating vocal actions in an articulatory plan ac counted for error profiles with simple syllabic structures both for some ch ildren with SLI and normal children with phonological performance lower tha n the age average. A severe difficulty with representing complex syllabic s tructures was a homogeneous characteristic of the group with SLI and worked as the main indicator of impaired, rather than simply slow, phonological d evelopment.