Comparison of Perceptual and Motor Responses to Changes in Intensity and Voice Fundamental Frequency

Abstract

There are twoseparate visual systems in the human brain -vision for perception and vision for action. The aim of this paper is to answer the question of whether perception-motor dissociation can also be found in auditory information processing. Previous studies have shown that in the case of changes of fundamental frequencyand sound pressure leveli na uditory feedback during vocalization, compensating motor reactions can be observed. The goal of the present experiments wast oe stablish the just noticeable differences in perception for both the voice fundamental frequencya nd sound pressure level. The established perception threshold values were used to determine if motor reactions observed in previous experiments might have occurred for stimuli that were perceptually unnoticed as judged by the present study.The results of both experiments showed that the values for which motor responses were observed are lower than the perceptual thresholds. These findings provide evidence supporting the theory of there being twosystems for auditory information processing: the motor system, which uses the acoustic signals of self-generated sounds to automatically adjust the acoustic parameters of the voice, and the perception system that consciously perceiveschanges in frequencyand sound pressure level.