Listener comprehension of severely dysarthric speech: effects of linguistic cues and stimulus cohesion.

This study is the second in a two-part series examining the effects of linguistic variables on listener processing of dysarthric speech. The first study (see K. C. Hustad & D. R. Beukelman, 2001) examined the effects of experimentally imposed topic cues, alphabet cues, and combined cues along with a control condition in which no cues were provided on intelligibility of unrelated and related sentences produced by 4 women with severe dysorthria secondary to cerebral palsy. The present study examined the effects of these same variables on listener comprehension of severely dysarthric speech produced by the same speakers. In addition, the relationship between intelligibility and comprehension was examined for each cue and stimulus cohesion condition. Consistent with intelligibility results, the present study found that combined cues resulted in higher comprehension scores than any other cue condition and that no cues resulted in lower comprehension scores than any other cue condition for both related and unrelated sentences. In addition, comprehension scores were higher for alphabet cues than for topic cues in the related-sentences condition. Findings dissimilar from intelligibility results were as follows: (a) comprehension scores associated with alphabet and topic cues did not differ for unrelated sentences, and (b) comprehension scores were higher for related than for unrelated sentences in each cue condition. Finally, significant positive relationships between intelligibility and comprehension data were found only for topic cues in the unrelated-sentences condition and for alphabet cues in the related-sentences condition.