The effect of deafness on the generation of voice

Abstract

The glottal source characteristics of 20 hearing‐impaired adolescents were investigated with a reflectionless tube [R. B. Monsen and A. M. Engebretson, J. Acoust. Soc. Am. 62, 981–993 (1977)]. Speakers phonated a neutral vowel in normal and soft voice and in polysyllabic words with primary stress on one syllable. These data were analyzed and compared with data from normal male and female adults and with glottal waves generated by the Flanagan‐Ishizaka two‐mass model of vocal‐fold vibration. It was found that (1) the glottal pulse produced by the deaf subjects, when considered as an isolated entity, is comparable to that of normal‐hearing speakers, although certain phonation abnormalities, such as diplophonia and creaky voice, occur quite commonly among the deaf subjects; and (2) the change of the glottal source over time, as controlled by the interaction of vocal‐fold tension and subglottal air pressure, is a primary deviant factor for many of the deaf speakers, and in particular the use of vocal‐fold tension as a frequency changing mechanism seems impaired by the subjects' deafness. [Supported by NINCDS Grant 03856.]