Modulation of auditory-vocal feedback control due to planned changes in voice fo.

Previous studies have demonstrated that voice fundamental frequency (fo), or pitch, relies on auditory feedback to monitor and correct for errors in production. When voice-pitch auditory feedback is unexpectedly perturbed, individuals typically produce a compensatory change in fo that opposes the direction of the pitch-perturbation. Studies comparing steady vowel vocalizations and speech tasks have demonstrated task-dependent modulation of the compensatory response, but the effects of planning to volitionally change fo during active vocalization have yet to be explored. Ten musicians and ten non-musicians were asked to perform two vocal tasks. Both tasks started off at a conversational fo. In one task, pitch-shifted feedback was presented when the participants were planning to hold fo constant (steady fo), and in the other, feedback was shifted while participants were in the planning stage prior to raising fo (raised fo) from a steady state. Acoustical analyses of fo were performed to measure the peak magnitude and latency of both the compensatory response as well as the voluntary fo change. Results showed that planning to change pitch modulates the mechanisms controlling feedback-based error correction of fo, and musicality affects how individuals incorporate modulations in auditory feedback with the feedforward plans to increase voice fo.