Knowing the Voice: Familiar Talkers in Speech Perception

Abstract

Millions of different people talk to each other, and no two people sound exactly the same. Yet, whomever we are listening to, we expect to easily understand what he or she has to say. Somehow, we adjust to each new talker’s voice and hear the “same” speech sounds. Until recently, differences between voices were viewed as a perceptual problem interfering with speech perception. Recent developments, however, have shown that familiar voices can facilitate speech. Speech-perception models can no longer dismiss talkers’ voices merely as carriers for speech, and models currently struggle to understand the relation between vocal identity and the content of speech. The present thesis contributed to this discussion by examining familiar talkers, whose identities have been encoded into listeners’ memories. Chapter 2 studied familiar faces’ and voices’ contribution to audiovisual speech processing, and found that different listeners may focus more strongly on learning either a familiar talker’s face or voice, but will recall what they have learned in response to that talker’s voice, not face. Chapter 3 examined self-speech, and discovered that we do receive a familiar-talker speech-processing advantage from hearing our own recorded voice, but only so far as we can identify self-voice; when voices are obscured by noise, we receive an equivalent advantage for all voices of our own sex. Chapter 4 confirmed a relation between speech familiarity and accurate talker identification. Taken together, the data presented in this thesis support a model of speech perception in which listeners encode talkers’ identities inclusive of both idiosyncratic speech production and vocal qualities and, when processing speech, recall as many of a talker’s identifying characteristics as can be usefully applied to an incoming speech signal. These findings contribute to our understanding of how we utilize talker identity in perceiving speech.