Intelligibility and acceptability of dysarthric speech produced at three different rates

This study investigated the abilities of speakers with dysarthria to increase or decrease their speech rate and the effects of such rate alterations on acceptability and intelligibility. Four speakers with mild to moderate, acquired dysarthria and two controls were audio-recorded reading sentences at three different rates: typical rate, increased rate, and decreased rate. Listeners were 15 unimpaired young adults. They rated sentences for acceptability (9-point interval scale from "terrible" through "excellent") and intelligibility (percent words correct).; Results indicated speakers could not consistently alter speaking rates. For acceptability, the impaired speakers had low acceptability scores across rates. Intelligibility results revealed ratings for the slow and typical conditions did not differ and were significantly higher than rates for the fast condition. As with earlier studies (Dagenais et al., 2006), results of this study suggest that what listeners prefer to listen to does not correspond with what they understand.