Auditory feedback control of voice fundamental frequency in school children.

The present study was intended to address how the online control of voice fundamental frequency (F(0)) during vocalization develops from school children to young adults. Nineteen school children (7-12 years old) and twenty-one young adults (19-27 years old) participated in this experiment. They were asked to sustain a vowel sound /u/ while their voice pitch feedback was randomly shifted (+/-50, +/-100, +/-200, and +/-500 cents) and fed back to them instantaneously over headphones. Results showed that school children produced significantly larger but slower compensatory responses to voice pitch feedback perturbations than young adults. Response latencies became longer with the increase in pitch perturbation magnitude, but no systematic changes were found as a function of stimulus direction. In addition, the number of responses "following" the stimulus direction across different stimulus magnitudes for school children was greater than for young adults. These findings demonstrate developmental changes of vocal responses to pitch feedback perturbations during vocalization from school children to young adults, and suggest that vocal responses can serve as an objective index of the maturation of the audio-vocal system.