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. KEY WORDS: hearing impaired, nasality, speaking rate, acoustic analysis, perception E xcessive nasality is a hallmark feature of the speech produced by deaf and /or severely hearing-impaired ( HI) individuals (Colton & Cooker, 1968; Fletcher & Daly, 1976; Hudgins, 1934; Penn, 1955; Seaver, Andrews, & Granata, 1980). Nasality is generally assumed to occur because of a lack of auditory feedback available to HI individuals. Without auditory feedback, a speaker may not learn the motor routines needed to separate the oral and nasal cavities, resulting in inadequate velopharyngeal (VP) closure and subsequent speech nasality. Further, excessive speech nasality encompasses perceptual as well as productive domains. Speech intelligibility is greatly reduced as a result of nasality present in the acoustic signal (Higgins, Carney, & Schulte, 1994; Hudgins & Numbers, 1942). Over 70 years ago, Hudgins (1934) concluded that improper use of the VP mechanism was the primary cause of increased speech nasality in HI individuals. This conclusion was based on a detailed study of speech breathing and the time taken to repeat phrases of varying lengths. Claire H. Dwyer Michael P. Robb Greg A. O’Beirne University of Canterbury, Christchurch, New Zealand Harvey R. Gilbert University of Connecticut, Storrs, CT Journal of Speech, Language, and Hearing Research • Vol. 52 • 1321–1333 • October 2009 • D American Speech-Language-Hearing Association 1092-4388/09/5205-1321 1321 Downloaded From: http://jslhr.pubs.asha.org/ by University Of Canterbury, Michael Robb on 03/30/2015 Terms of Use: http://pubs.asha.org/ss/Rights_and_Permissions.aspx