Instructing subjects to make a voluntary response reveals the presence of two components to the audio-vocal reflex

Abstract

Previous findings have shown that subjects respond to an alteration, or shift, of auditory feedback pitch with a change in voice fundamental frequency (F0). When pitch shifts exceeding 500 ms in duration were presented, subjects' averaged responses appeared to consist of both an early and a late component. The latency of the second response was long enough to be produced voluntarily. To test the hypothesis that there are two responses to pitch-shift stimuli and to clarify the role of intention, subjects were instructed to change their voice F0 in the opposite direction of the pitch-shift stimulus, in the same direction, or not to respond at all. In a second group, subjects were tested under the above conditions as well as under instructions to raise voice F0 or to lower F0 as rapidly as possible upon hearing a pitch shift. Results showed that, when given instructions to produce a voluntary response, subjects made both an early vocal response (VR1) and a later vocal response (VR2). The second response, VR2, was almost always made in the instructed direction, whereas VR1 was often made incorrectly. The latency of VR1 was reduced under instructions to respond to feedback pitch shifts by changing voice F0 in the opposite direction, compared with that when told to ignore the pitch shifts. Latency and amplitude measures of VR2 differed under the various experimental conditions. These results demonstrate that there are two responses to pitch-shift stimuli. The first is relatively automatic but may be modulated by instructions to the participant. The second response is probably a voluntary one.

Interactions between auditory and somatosensory feedback for voice F 0 control

“…In an attempt to provide a quantitative hypothesis, we extended a previously presented model of F 0 control incorporating auditory feedback (Hain et al 2000), to include kinesthetic feedback. With our model we simulated our data and showed feasibility for a simple linear feedback implementation.…”

“…We extended a linear model of F 0 control (Hain et al 2000) using auditory feedback to include kinesthetic input. This model topology is structured in a similar way to the speech production model of Guenther et al (2006), having both a feedforward and feedback pathway, and auditory and kinesthetic feedback.…”

“…Other studies demonstrated that masking of auditory feedback led to a deterioration in fine control of F 0 and inaccuracy in singing musical notes (Elliott and Niemoeller 1970;Mallard et al 1978;Mürbe et al 2002). Presentation of sudden perturbations in voice auditory pitch feedback while subjects are speaking or sustaining a vowel sound have demonstrated compensatory changes in voice F 0 production (Burnett et al 1998;Chen et al 2007;Donath et al 2002;Hain et al 2000;Jones and Munhall 2002;Kawahara 1995;Larson et al 2001;Natke and Kalveram 2001;Sapir et al 1983;Xu et al 2004). …”

“…First consider the case of our previous work where voice auditory pitch feedback was experimentally shifted while kinesthesia was left intact (Burnett et al 1998;Hain et al 2000;Larson et al 2001;Xu et al 2004). To the extent that kinesthetic feedback contributes to stabilization of F 0 , experimental inferences that neglect kinesthetic feedback should result in an incorrectly low estimate of the coupling between auditory error and F 0 error (F gain and F Tc in Fig.…”

Pitch Processing of Speech: Comparison of Psychoacoustic and Electrophysiological Data

“…A variety of studies have demonstrated that the introduction of changes to real time auditory feedback (to self-generated sounds during vocalization) elicits compensative reactions with a latency of 100-150 ms in listeners, with speech sounds (Xu et Hafke, 2008). It has been shown that compensative reactions to shifts in fundamental frequency remain the same when the listeners follow instructions not to respond to changes in feedback (Hain et al, 2000). In the aforementioned studies, various interval values were used to introduce changes in the voice fundamental frequency.…”