Coarticulation within and between syllables by children with developmental apraxia of speech

W. J. M. Levelt & L. Wheeldon's (1994) hypothesis that a mental syllabary mediates between phonology & motor output is tested in the productions of Dutch children (N = 6 males, aged 5:0-5:11) with developmental apraxia of speech & age-matched controls by manipulating a syllable boundary in sequences of schwa + /s/ + /x/ + vowel. Types & %s of speech errors are tabulated for each subject in the /s#x/ & /#sx/ conditions; results indicate that reduction of /sx/ to /s/ or to /x/ is significantly more frequent for /sx/ onset clusters than for /s/ + /x/ across a syllable boundary & that a pause is more frequent in the latter condition. Subjects show significantly stronger anticipatory coarticulation for both /s/ & /x/ than do controls & lack the systematic boundary-dependent difference in relative duration found in controls. It is concluded that children with developmental apraxia of speech evidence deficits in both syllabic programming & motor planning. 1 Table, 2 Figures, 8 References. J. Hitchcock