Study on the perception of nonlinguistic information of noise-vocoded speech under noise and/or reverberation conditions

It has been known that noise and reverberation greatly affect the perception of linguistic information, in particular speech intelligibility. However, the effect of noise and reverberation on the perception of non-linguistic information has not been clarified. We investigated how these types of disturbances affect the perception of non-linguistic information (speaker individuality and vocal emotion) of noise-vocoded speech. We conducted speaker-distinction and vocal-emotion-recognition experiments using noise-vocoded speech created from the speech in noisy, reverberation, and noisy reverberant environments as stimuli. We used seven noise conditions (signal-to-noise ratio (SNR) = oo, 20,15,10, 5, 0, -5 dB) and six reverberation conditions (reverberation time (TR) = 0.0, 0.1, 0.3, 0.5,1.0, 2.0 s). In both speaker-distinction and vocal-emotion-recognition experiments, the main effects of noise and reverberation were significant, but the interaction was not significant. From these results, except for extremely poor sound conditions, under daily noise and reverberation conditions (an SNR of more than 10 dB and TR less than 1.0 s), there were no significant effects of noise and reverberation.