Abstract:
Particular manipulations in auditory feedback pitch differentially affect voice F0 [Burnett et al., J. Voice (in press)]. Subjects who sustained constant-pitch phonation of the vowel /a/ with auditory feedback set at a masking-loudness level appeared to produce a multicomponent voice F0 change following upward or downward directed shifts in feedback pitch. The first response appeared to be relatively automatic, with a latency of approximately 150 ms and a consistent response direction opposite the stimulus direction. The second, more variable response appeared to arise from a voluntary effort to adjust voice F0. Until now, the characteristics of this second response were hidden by its close temporal proximity to the first response. The purpose of this study was to separate and further study these two responses through manipulation of task instructions. Subjects were alternately instructed to ignore the auditory feedback pitch shifts, change their pitch in the same direction as the pitch shift, or change their pitch in the opposite direction. Through this method, the duration of the first response and the latency of the second response were determined. The results are consistent with and expand upon the previous findings of two voice F0 response components.