Some characteristics of the glottal sound source of deaf children

The glottal source of 28 hearing‐impaired and five normally hearing adolescents is compared with respect to the waveshape produced and the spectrum. The measurement device used employs a uniform reflectionless tube, recently described by M. M. Sondhi [J. Acoust. Soc. Am. 55, 396 (1974)]. Among the variety of glottal waveshapes produced by normal talkers, the opening phase of the wave appears typically less steep and is longer than the closing phase. In contrast, many of the deaf subjects commonly produce a waveshape reversed in phase with respect to normal: the opening phase is shorter and steeper than the closing phase. Such phase differences need not be a primary factor in abnormal voice quality. However, the abnormal laryngeal control necessary to produce the observed waveshapes may adversely affect the normal production of speech sounds. [Supported by NINDS Grant NS 03856.]