Perceptual sensitivity to changes in vocal fold geometry and stiffness.
Zhaoyan Zhang, Jody E. Kreiman, Bruce R. Gerratt · The Journal of the Acoustical Society of America · 2011
Control of vocal quality is a primary goal of speech and the focus of clinical management of voice disorders. Therefore, it can be argued that auditory-perceptual sensitivity to the acoustic changes that occur as a laryngeal parameter is manipulated should be considered in the development of physiologic models of phonation. Listener perception of the effects of change in vocal fold geometry (medial surface thickness and vocal fold depth) and stiffness will be investigated by measuring the just-noticeable difference (JND) to acoustic stimuli generated by physical models differing in these three model parameters. The acoustic pressure produced by physical models differing in small steps in each model parameter will be recorded and normalized for F0. Listeners will hear pairs of these acoustic stimuli in a same/difference task and JNDs will be calculated for each parameter. Data will be interpreted by comparing the JND for each model parameter to the range of values for that parameter. Results will be discussed with regard to which vocal fold parameters are most important for generating perceptually relevant and thus clinically meaningful changes in quality, thus validating their inclusion in physical models of phonation. [Work supported by NIH.]