Accuracy of Articulation Rate Control with Visual Feedback in Persons who do and do not Stutter

The ability to control speech rate with real-time visual feedback was compared between people who do and do not stutter (PWS/PWNS). Nine PWS and 7 PWNS participated in the study. Fifteen sentences were read aloud after repeating a played-back sentence twice in each of 6 trials at 6 different target speeds. The 6 trials comprise a session, and there were 3 sessions (A1, B, A2) with only the second session (B) accompanied by real-time visual feedback of the subject's speech rate and the target speed. The speech rate excluding pauses or dysfluencies was significantly reduced in B and A2 from that in session A1. Although there was no difference in speech rate between B and A2, (a) there was an interaction between the target rate and the group in session B, and (b) the variability in the error of the PWS was larger than that of the PWNS in the retention session (A2). These results suggests (a) that at least some of the PWS use a different strategy in controlling their speech rate than PWNS, and (b) that some of the PWS were less accurate in retaining the learned speech rate in the previous session B with visual feedback than the PWNS, although they did use the visual feedback information and learned the speech rate, to a similar averaged accuracy during the feedback.