Date of Award
6-1990
Degree Name
Master of Arts
Department
Speech, Language and Hearing Sciences
First Advisor
Dr. James M. Hillenbrand
Second Advisor
Dr. Robert L. Erickson
Third Advisor
Dr. John M. Hanley
Fourth Advisor
Dr. Richard Pippen
Access Setting
Masters Thesis-Open Access
Abstract
This study investigated the perceptual effects of varying glottal waveshape perturbation, duty cycle perturbation, jitter, signal-to-noise ratio perturbation, and shimmer at three levels of perceived magnitude (high, medium, and low). Voice signals were synthesized using a modified version of Klatt's (1980) formant synthesizer. Listeners rated signal dysphonia using an A-B dissimilarity procedure. Multidimensional scaling analysis suggested that signals judged low in magnitude of dysphonia were perceived to be most similar. Medium-level and high-level magnitude signals were judged to be respectively less similar. Signals varying in duty cycle and fundamental frequency perturbation were perceived to be very similar while those signals varying in waveshape and amplitude perturbation were consistently judged to be most different from all other signals within each level of perceived severity. Implications for the development of objective measures vocal quality are discussed.
Recommended Citation
Nero, Richard E., "Perceptual Effects of Perturbation and Additive Noise" (1990). Masters Theses. 1089.
https://scholarworks.wmich.edu/masters_theses/1089