Relative contributions of amplitude and phase for speech perception

Abstract

This study investigated the relative contributions of amplitude and phase in speech perception using three types of stimuli: amplitude-based vocoded stimuli, phase-based vocoded stimuli and fine-structure (FS) stimuli. Listening experiments with normal-hearing participants showed consistent findings with previous studies that the intelligibility of both amplitude-based vocoded stimuli and phase-based vocoded stimuli increased with an increase in the numbers of channels in synthesizing the signals, while the intelligibility of FS stimuli decreased with an increase in the numbers of channels. This study also agreed with the previous findings that the success of speech perception was due to the temporal envelope cues recovered by the auditory system. After making pairwise comparison, the overall low intelligibility of phase-based vocoded stimuli and the large difference between phase-based vocoded stimuli and FS stimuli should be taken into consideration for the future study.