Perceptual-phonetic predictors of single-word intelligibility: a study of Cantonese dysarthria

This study investigated the perceptual-phonetic predictors of intelligibility in Cantonese speakers with dysarthria. The speakers were 20 young adults with cerebral palsy. The listener group consisted of 12 native Cantonese speakers. A single-word intelligibility test was constructed, based on 17 phonetic contrasts. There were no significant differences in intelligibility for gender, age, or type of cerebral palsy. A regression analysis showed that intelligibility could be predicted with 97% accuracy by 5 out of the 6 most problematic contrasts. Three contrasts (glottal vs. null, final vs. null, and long vs. short vowel) predicted variation on an independent intelligibility measure obtained for the same speakers with 84% accuracy. Principal components analysis derived 4 components, which accounted for 81% of the variance in the 17 contrasts. Physiological explanations and language-specific contributions to speech disorder in this group of speakers are discussed.