Sentence intelligibility and acoustic contrast in adults with cerebral palsy

By G. Turner and K. Hustad

The motor speech disorder associated with cerebral palsy (CP) often leads to deficits in speech intelligibility into adulthood. In attempts to understand the underlying factors responsible for speech intelligibility deficits in adults with CP, research has focused on evaluating the contributions of various phonetic and acoustic variables to word intelligibility (Ansel & Kent, 1992; Platt, Andrews & Howie, 1980). To acquire a broader understanding of the intelligibility deficit s in individuals with CP, this type of work should be extended beyond a word level analysis to different speech materials (Weismer, Jeng, Laures, Kent & Kent, 2000). In previous research by Ansel and Kent (1992), four acoustic contrasts accounted for over 60% of the variability in word intelligibility scores. The purpose of this study was to evaluate the relationship of acoustic contrasts (e.g., tense/lax vowel duration difference) previously used to predict word intelligibility and apply them to the study of sentence intelligibility for adults with CP. Further, vowel space and F2 slope, variables with known predictive value for other times of dysarthria were included. These measures were subjected to a multiple regression analysis and results will be discussed.