VOICE F0 RESPONSES TO MANIPULATIONS IN PITCH FEEDBACK

Recent studies have shown that when phonating subjects hear their voic e pitch feedback shift upward or downward, they respond with a change in voice fundamental frequency (F0) output. Three experiments were per formed to improve our understanding of this response and to explore th e effects of different stimulus variables on voice F0 responses to pit ch-shift stimuli. In experiment 1, it was found that neither the absol ute level of feedback intensity nor the presence of pink masking noise significantly affect magnitude or latency of the voice F0 response. I n experiment 2, changes in stimulus magnitude led to no systematic dif ferences in response magnitudes or latencies. However, as stimulus mag nitude was increased from 25 to 300 cents, the proportion of responses that changed in the direction opposite that of the stimulus (''opposi ng'' response) decreased. A corresponding increase was observed in the proportion of same direction responses (''following'' response). Tn e xperiment 3, increases in pitch-shift stimulus durations from 20 to 10 0 ms led to no differences in the F0 response. Durations between 100 a nd 500 ms led to longer duration voice F0 responses with greater respo nse magnitude, and suggested the existence of a second F0 response wit h a longer latency than the first. (C) 1998 Acoustical Society of Amer ica.