The effect of rate control on speech rate and intelligibility of dysarthric speech.
OBJECTIVE
This study investigated the effect of rate control methods (RCMs) on speaking rate (SR), articulation rate (AR), and intelligibility in dysarthric speakers.


METHODS
Nineteen dysarthric patients (7 unilateral upper motor neuron dysarthria, 6 hypokinetic, 3 flaccid, 3 ataxic) participated. SR, AR and intelligibility ratings were determined on the basis of 1-min recorded reading passages. Seven RCMs were applied: voluntary rate control, hand tapping, alphabet board, pacing board and delayed auditory feedback with a delay of 50, 100 and 150 ms.


RESULTS
Almost all methods resulted in lower mean SRs and ARs (p < 0.05). Rate control did not improve overall intelligibility of the dysarthric population. However, a meaningful increase of intelligibility was found in 5 participants. This study indicates that the effect of rate control on intelligibility is independent of habitual speech rate and type of dysarthria. Degree of intelligibility may be an influencing factor. The most effective methods are: voluntary rate control, alphabet board, hand tapping and pacing board.


CONCLUSIONS
RCMs do result in lower speech rates. Some dysarthric individuals do benefit from one or more RCMs, but rate control may also have an inverse effect on intelligibility.
Van Nuffelen
Gwen
G
Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Antwerp University Hospital, Antwerp, Belgium. gwen.van.nuffelen@telenet.be
De Bodt
Marc
M
Wuyts
Floris
F
Van de Heyning
Paul
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004401:Dysarthria / Q000523:psychology / Q000628:therapy*; D030141:Feedback, Psychological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D011932:Reading; D015203:Reproducibility of Results; D013060:Speech; D013065:Speech Intelligibility; D013068:Speech Production Measurement; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult