Digital Computer System for Dynamic Analysis of Speech and Sound Feedback Mechanisms

The aim of the research reported is to put the laboratory application of closed-loop digital computer systems to experimental control and analysis in biology and behavioral science on a formal basis, using special concepts of programming to quantitatively control different parameters of variation in sensory feedback of specific response systems. The theory is unconventional in that the computer and the techniques of closed-loop programming are designed to control time delays, space displacements, kinetic modulations, and informational and symbolic transformations in the sensory feedback that is generated by movements and/or physiological actions of the living subject.

The present experiment illustrates application of the system and the methods of closed-loop perturbation programming to study of delayed auditory feedback of speech. The subject's speech is transduced, amplified, converted by an analog-to-digital converter, programmed for delays, deconverted by a digital-to-analog converter, filtered, amplified, and then used to activate protected earphones on the speaker's ears. The computer is also used to introduce many special perturbation of the auditory feedback of speech in real time.