Voice F0 responses to actual versus consciously perceived auditory feedback pitch shifts

Abstract

The purpose of this study was to determine the effect of pitch shift discrimination ability on production of voice F0 responses to auditory feedback pitch shifts. Subjects repeatedly vocalized /u/ into a microphone while listening to their voice fed back over headphones. During each trial, auditory feedback pitch was experimentally shifted upward or downward (randomly determined) by 50 cents for 100 ms. Subjects subsequently pressed a button labeled up or down to indicate their perceived direction of voice feedback pitch shift. Voice output was recorded, F0 extracted, smoothed, time aligned to the onset of the pitch shift, and averaged. Button response accuracy was found to be at chance expectancy among the majority of subjects. Nevertheless, all subjects responded vocally to the pitch shifts by changing voice F0 in the opposite direction, indicating that the direction of the shift was indeed processed by the auditory system. These results are consistent with the existence of preattentive mechanisms of audio‐vocal control, and provide evidence for a mismatch between conscious and preattentive auditory processing of voice pitch feedback for the control of voice F0. [Work supported by NINDS.]