Effect on timbre perception between zero phase and non-zero phase by bandwidth difference of group delay

摘要

This report describes the results of the subjective experiment for investigating the characteristic of human phase perception. In the experiment, we use the stimuli which have flat amplitude spectrum and have certain group delay value only in a particular frequency band. The first experiment is performed using stimuli with different group delay peak value, fixed center frequency of group delay which is 1000Hz and 4000Hz, and fixed frequency bandwidth of group delay computed by multiplying ERB and certain coefficient together. As a result, when the peak value of stimuli is between - 1ms and 2ms, the stimuli is perceived to be zero phase regardless of the center frequency and the bandwidth. Moreover, when the peak value is less than -8ms or more than 10ms and the bandwidth is less than 1ERB, each of the stimuli is perceived to be similar. This result indicates the non-zero phase stimuli are similar each other when the bandwidth is less than 1ERB. It is also found that the similarity of the stimuli becomes lower, as the bandwidth of the non-zero phase stimuli is more than 1ERB.