Contours of voice F0 (top trace), auditory feedback (middle trace), and TTL pulses (bottom traces) (A) and two representative averaged vocal responses to −100 cents (B) and +100 cents (C) pitch-shifted stimuli.

For Figure 1A, the arrows in the contour of auditory feedback denote the upward and downward pitch-shifted stimuli (100 cents). For Figures 1B and 1C, horizontal dense dotted lines represent ±2 standard deviations of the pre-stimulus mean averaged F0. Vertical dashed lines indicate the onset and offset times of the responses. Horizontal sparse dashed lines indicate the response magnitude as reflected by the maximal or the minimal value of the average response. Time 0 represents the onset of pitch-shift perturbation.