ACOUSTIC EVIDENCE FOR THE DEVELOPMENT OF GESTURAL COORDINATION IN THESPEECH OF 2-YEAR-OLDS - A LONGITUDINAL-STUDY

Studies of child phonology have often assumed that young children firs t master a repertoire of phonemes and then build their lexicon by form ing combinations of these abstract, contrastive units. However, eviden ce from children's systematic errors suggests that children first buil d a repertoire of words as integral sequences of gestures and then gra dually differentiate these sequences into their gestural and segmental components. Recently, experimental support for this position has been found in the acoustic records of the speech of 3-, 5-, and 7-year-old children, suggesting that even in older children some phonemes have n ot yet fully segregated as units of gestural organization and control. The present longitudinal study extends this work to younger children (22- and 32-month-olds). Results demonstrate clear differences in the duration and coordination of gestures between children and adults, and a clear shift toward the patterns of adult speakers during roughly th e third year of life. Details of the child-adult differences and devel opmental changes vary from one aspect of an utterance to another.