Breaking voice identity perception: Expressive voices are more confusable for listeners

Abstract

The human voice is a highly flexible instrument for self-expression, yet voice identity perception is largely studied using controlled speech recordings. Using two "voice sorting" tasks with naturally-varying stimuli, we compared the performance of listeners who were familiar and unfamiliar with the TV show Breaking Bad: listeners organized audio clips of speech with 1) low and 2) high expressiveness into perceived identities. We predicted that increased expressiveness (e.g. shouting, whispering) would significantly impair performance. Overall, while unfamiliar listeners were less able to generalise identity across exemplars, the two groups performed equivalently well on telling voices apart. However, high vocal expressiveness significantly impaired telling apart in both groups: this led to increased misidentifications, where sounds from one character were assigned to the other. Our data suggest that vocal expressiveness has powerful and complex effects on identity perception leading to complex interacting effects of stimulus and listener characteristics.