Imitation of intonation contours by children with normal and disordered language development

This study investigated the relation between intonation and segmental phonology in children with developmental language impairment (LI). Eleven 4-year-olds with LI and 11 age-matched children with normal language development imitated sentences that were modelled with different nuclear tones. Instrumental analysis indicated that the children imitated falling tones more accurately than rising tones, but there were no group differences. Although the children with LI had age-appropriate intonation skills, they all demonstrated mild to moderate impairments in segmental phonology. This dissociation pattern was confirmed by correlation analyses, which indicated that the severity of a child's articulation disorder predicted how well he or she produced segmental contrastsA but not prosodic contrasts. The findings are discussed in relation to the hypothesis that prosody pertains to a different 'tier' of the grammar than other phonological systems, and that the speech of children with LI may reflect asymmetrical degrees of impairment across prosodic and non-prosodic tiers.