Acoustic and linguistic factors affecting perceptual dissimilarity judgments of voices

The human voice is a complex acoustic signal that conveys talker identity via individual differences in numerous features, including vocal source acoustics, vocal tract resonances, and dynamic articulations during speech. It remains poorly understood how differences in these features contribute to perceptual dissimilarity of voices and, moreover, whether linguistic differences between listeners and talkers interact during perceptual judgments of voices. Here, native English- and Mandarin-speaking listeners rated the perceptual dissimilarity of voices speaking English or Mandarin from either forward or time-reversed speech. The language spoken by talkers, but not listeners, principally influenced perceptual judgments of voices. Perceptual dissimilarity judgments of voices were always highly correlated between listener groups and forward/time-reversed speech. Representational similarity analyses that explored how acoustic features (fundamental frequency mean and variation, jitter, harmonics-to-noise ratio, speech rate, and formant dispersion) contributed to listeners' perceptual dissimilarity judgments, including how talker- and listener-language affected these relationships, found the largest effects relating to voice pitch. Overall, these data suggest that, while linguistic factors may influence perceptual judgments of voices, the magnitude of such effects tends to be very small. Perceptual judgments of voices by listeners of different native language backgrounds tend to be more alike than different.