title: Dysarthric sentence intelligibility: contribution of iconic gestures and message predictiveness.
abstract: This study examined changes in the sentence intelligibility scores of speakers with dysarthria in association with different signal-independent factors (contextual influences). This investigation focused on the presence or absence of iconic gestures while speaking sentences with low or high semantic predictiveness. The speakers were 4 individuals with dysarthria, who varied from one another in terms of their level of speech intelligibility impairment, gestural abilities, and overall level of motor functioning. Ninety-six inexperienced listeners (24 assigned to each speaker) orthographically transcribed 16 test sentences presented in an audio + video or audio-only format. The sentences had either low or high semantic predictiveness and were spoken by each speaker with and without the corresponding gestures. The effects of signal-independent factors (presence or absence of iconic gestures, low or high semantic predictiveness, and audio + video or audio-only presentation formats) were analyzed for individual speakers. Not all signal-independent information benefited speakers similarly. Results indicated that use of gestures and high semantic predictiveness improved sentence intelligibility for 2 speakers. The other 2 speakers benefited from high predictive messages. The audio + video presentation mode enhanced listener understanding for all speakers, although there were interactions related to specific speaking situations. Overall, the contributions of relevant signal-independent information were greater for the speakers with more severely impaired intelligibility. The results are discussed in terms of understanding the contribution of signal-independent factors to the communicative process.
authors.affiliation: Kansas State University, Manhattan, USA. jgarcia@humec.ksu.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Garcia
authors.forename: P A
authors.initials: PA
authors.lastname: Dagenais
mesh_terms: D000328:Adult; D000368:Aged; D004401:Dysarthria / Q000175:diagnosis*; D005260:Female; D005868:Gestures; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012660:Semantics; D012720:Severity of Illness Index; D013065:Speech Intelligibility; D013068:Speech Production Measurement