Acoustic and Perceptual Comparisons of Imitative Prosody in Kindergartners with and without Speech Disorders

This study investigated the affiliation of prosody with childhood articulation disorders. The Tennessee Test of Rhythm and Intonation Patterns, T-TRIP (Koike & Asp, 1981), was used to determine if kindergartners with linguistic (i.e. phonological) speech disorders, oral-motor speech disorders, or normal speech performed differently on imitative prosody tasks. Performance was assessed perceptually with T-TRIP overall and subtest scores, and acoustically with measurements of individual prosodic variables (amplitude, duration, and fundamental frequency) on selected items from the rhythm and intonation subtests. Perceptual and acoustic data were examined for characteristic patterns of performance by individual subjects and by groups. A Kruskal-Wallis ANOVA of the perceptual scores revealed that the three groups performed differently on the T-TRIP rhythm, and intonation subtests, and on the total score. Specifically, the oral-motor group had the lowest range of scores and was clearly separated from the other two groups. No group cut-off scores were established since the linguistic group’s scores slightly overlapped the control groups’ range of scores. Acoustic results generally supported the findings of earlier studies of stress and intonation. Correct responses contained a wide selection of acoustic patterns, while incorrect responses consisted of error patterns resembling those of younger children. Subjects with speech disorders demonstrated several characteristic error patterns: linguistic subjects tended to add syllables and to lexicalize items, while oral-motor subjects tended to delete syllables and to convert iambic stress into trochaic. Overall, whether T-TRIP responses were examined by perceptual or acoustic methods, the oral-motor group’s imitative prosody ability was significantly different than the other groups’ performance. The clinical implications of this finding are that the T-TRIP has the potential to be used as a screening tool to identify subjects whose difficulties with imitative prosody are consistent with oral-motor speech disorders, specifically DVD