Voice F0 responses to feedback pitch are not affected by speed of stimulus onset

Abstract

Voice F0 appears flexibly controlled by interactions between voluntary mechanisms, memory, and auditory feedback. Previous studies have shown that voice F0 is changed following an abrupt shift in feedback pitch [Elman, 1981; Kawahara, 1994; Larson et al., 1995]. In order to establish that this response is due to the pitch of the feedback shift rather than its onset speed, an experiment was conducted in which voice feedback pitch heard loudly through headphones was slowly or quickly decreased to 100 cents lower than the steady voice F0 produced by the subjects. Subjects were instructed to maintain steady F0 production regardless of any feedback changes they might hear. Both slow and fast ramping pitch shift stimuli (PSS) generally elicited opposing responses characterized by a rising voice F0 which mirrored the slope of the lowering PSS ramp. Accordingly, response latency and time of peak response were inversely related to the slope of the PSS ramp; the lower the slope, the later the response latency and peak. Peak response magnitude was not affected by ramp speed. These results suggest that the auditory–vocal system continuously monitors auditory feedback and adjusts vocal output so as to reduce the difference between it and a reference signal.