The operant manipulation of vocal pitch in normal speakers.

Abstract

A device consisting of variable electronic filters and voice-actuated relays was used to raise or lower the vocal pitch of four normal-speaking subjects by the differential reinforcement of selected frequencies emitted by them during oral reading. Continuous, fixed interval, fixed ratio, and variable interval reinforcement schedules were applied to each subject. The results of the study indicated that fundamental vocal frequency is a manipulable operant response. All reinforcement schedules examined produced high rates of response at the selected frequency for all subjects. The variable interval schedules produced the most consistent, high durations of response for all subjects. The method of manipulation of fundamental frequency investigated in the study appears to have promise as a therapeutic technique, especially for deaf speakers and clients with functional pitch disorders.