Contributors to Intelligibility in Preschool-Aged Children with Cerebral Palsy

Purpose: This study investigated the contribution of vowel space, articulation rate, maximum utterance length, and language skills to intelligibility in 30- to 36-month-old children with cerebral palsy (CP). We also examined differences among variables for three subgroups of children with CP and a small group of typically developing (TD) children. Method: Nineteen children with CP and five TD children provided speech samples, and 120 listeners transcribed the speech samples. Acoustic analysis of temporal and vowel spectral measures was completed on single-word productions. Results: Vowel space was the only variable that made a significant and independent contribution to intelligibility, although all variables collectively accounted for 74% of the variance in intelligibility scores. TD children tended to have larger vowel spaces than children with CP even among children with CP who had intelligibility scores within the range of TD children. Conclusions: Of children with CP who were able to talk at 30 to 36 months of age, 60% had clinical speech or language deficits. Production of vowels appears to make an important contribution to intelligibility, and for many children with CP, considerable deficits in intelligibility may be evident by the age of 3 years. Early interventions targeting both speech and language may improve intelligibility and functional communication skills.