Effective Part of Auditory Stimuli for Evoking Brain Stem Response

Abstract

Effective parts of tone pips to evoke anditory brain stem response (ABR-Na) were studied using 6 cats. Amplitudes of the responses evoked by equal-slope-tone-pips with different rise-times were analysed at three frequencies (500, 1000 and 2000Hz). The results indicated that the effective parts measured from onset were more than 4msec at 500 and 1000Hz, and more than 2msec at 2000Hz. Each cycle of this range contributed to evoke the responses, at weak intensity level above response thresholds. Contribution of the initial part of the tone pips was larger as the slpoe was broadened. The results of this experiments provide useful informations to determine the appropriate stimuli for objective audiometry.