ASA 127th Meeting M.I.T. 1994 June 6-10

5pSP22. Speech production before and after deafening.

Res. Lab. of Electron., Rm. 36-511, MIT, Cambridge, MA 02139

The role of hearing in speech production was investigated by analyzing the speech of an adult female before and after she experienced sudden, substantial hearing loss. Prior to the onset of this loss, she had a mild-to-moderate hearing loss in one ear (aided), and was deaf in the other due to bilateral acoustic neuromas. She became deaf bilaterally when the second of these neuromas was surgically removed. Following this surgery, an auditory brainstem implant provided minimal speech reception benefit. Three speech production recordings made prior to deafening were compared to recordings made 11 and 35 weeks post-deafening. Results indicated significant changes in voice onset time (VOT), fundamental frequency (F0), F0 range, and vowel duration. VOTs, adjusted for changes in syllable duration [Lane et al., J. Acoust. Soc. Am. (to be published)], were significantly shorter for the voiceless plosives post-deafening. F0 was at the mean of a normative range [Holmberg et al., J. Voice 3, 294--305 (1989)] prior to deafening, and rose significantly above this range post-deafening. An analysis of prosody indicated that the subject placed pitch accents on the same syllables post-deafening, but F0 mean and s.d. were significantly higher. Vowel formants, /s--sh/ contrast, an indirect measure of breathiness, and overall SPL, showed no significant changes by 35 weeks post-deafening. [Work supported by NIDCD.]