Reflexive and volitional voice fundamental frequency responses to an anticipated feedback pitch error

The pitch-shift reflex is a corrective voice fundamental frequency (F0) response triggered by a sudden shift or "error" in auditory feedback pitch. We investigated how anticipating a voice pitch error affects the pitch-shift reflex and volitional voice F0 responses. Adults sustained the vowel/u/at a comfortable pitch and pressed a button to deliver a 100 cent, 100 ms auditory feedback pitch shift immediately or after a random delay. Pitch shift direction was either constant (up) or randomized (up or down). Onset anticipation often resulted in an anticipatory voice F0 change, but stimulus direction predictability did not affect the responses. When pitch error onset and direction were both anticipated, some participants produced an ideomotor voice F0 change that partially imitated the error, but they produced no apparent pitch-shift reflex. Results imply that when voice pitch errors are anticipated, volitional voice F0 responses may reduce or enhance voice F0 stability.