Incomplete compensation to articulatory perturbation.

Measurements were made of vowels, fricatives, and stop consonants produced by 15 adult speakers of French in one free-mandible and two fixed mandible conditions. Speech acoustic data were recorded immediately upon bite-block insertion and after a 15-min accommodation period. Results indicate that compensation to increased jaw opening during speech is neither immediate nor complete as there were small but significant differences in the acoustic parameters of vowels and consonants produced under bite-block and normal conditions. Further, the data suggest that, at least for vowels, speech compensatory strategies may develop over time, perhaps involving error-based correction. Consonants appear to require a more lengthy period of speech adaptation, and this may be due to the articulatory requirements for their accurate production. Individual differences in compensatory abilities are also discussed.