Dept. of Mech. Eng. and Res. Lab. of Electron., MIT, Cambridge, MA 02139
One practical aim of this research is to determine how best to use speech recognition techniques for augmenting the communication abilities of dysarthric speakers. As a first step toward this goal, the following kinds of analyses and tests have been performed on words produced by several dysarthric speakers: a closed-set intelligibility test based on Kent et al. [J. Speech Hear. Disord. 54, 482--499 (1989)]; an open intelligibility test; critical listening and transcription; acoustic analysis of selected utterances; and an evaluation of the recognition of words by a commercial speech recognizer. The data from one speaker have been examined in detail. The analysis and testing have led to several conclusions concerning the control of the articulators for this speaker: production of obstruent consonants was a particular problem (only 30% of syllable-initial obstruents were produced with no error), whereas sonorant consonants were less of a problem (70% correct). Of the obstruent errors, most were voicing errors, but place errors for alveolars (particularly fricatives) were also high, and these consonants were produced inconsistently, as inferred from acoustic analysis and from low scores from the recognizer for words with these consonants. In comparison, vowel errors were less prevalent. Implications for the use of a speech recognizer for augmenting this speaker's communication abilities are discussed.