The influence of speaking rate on nasality in the speech of hearing-impaired individuals.

Purpose: The purpose of this study was to determine whether deliberate increases in speaking rate would serve to decrease the amount of nasality in the speech of severely hearing-impaired individuals.

Method: The participants were 11 severely to profoundly hearing-impaired students, ranging in age from 12 to 19 years (M = 16 years). Each participant provided a baseline speech sample (R1) followed by 3 training sessions during which participants were trained to increase their speaking rate. Following the training sessions, a second speech sample was obtained (R2). Acoustic and perceptual analyses of the speech samples obtained at R1 and R2 were undertaken. The acoustic analysis focused on changes in first (F(1)) and second (F(2)) formant frequency and formant bandwidths. The perceptual analysis involved listener ratings of the speech samples (at R1 and R2) for perceived nasality.

Results: Findings indicated a significant increase in speaking rate at R2. In addition, significantly narrower F(2) bandwidth and lower perceptual rating scores of nasality were obtained at R2 across all participants, suggesting a decrease in nasality as speaking rate increases.

Conclusion: The nasality demonstrated by hearing-impaired individuals is amenable to change when speaking rate is increased. The influences of speaking rate changes on the perception and production of nasality in hearing-impaired individuals are discussed.