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 organised audio clips of speech with (1) low-expressiveness and (2) high-expressiveness into perceived identities. We predicted that increased expressiveness (e.g., shouting, strained voice) would significantly impair performance. Overall, while unfamiliar listeners were less able to generalise identity across exemplars, the two groups performed equivalently well when telling voices apart when dealing with low-expressiveness stimuli. However, high vocal expressiveness significantly impaired telling apart in both the groups: this led to increased misidentifications, where sounds from one character were assigned to the other. These misidentifications were highly consistent for familiar listeners but less consistent for unfamiliar listeners. Our data suggest that vocal flexibility has powerful effects on identity perception, where changes in the acoustic properties of vocal signals introduced by expressiveness lead to effects apparent in familiar and unfamiliar listeners alike. At the same time, expressiveness appears to have affected other aspects of voice identity processing selectively in one listener group but not the other, thus revealing complex interactions of stimulus properties and listener characteristics (i.e., familiarity) in identity processing.

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

“…failing to perceive different exemplars of the same voice as belonging to the same identity). This study thus replicated previous findings from face sorting tasks (Jenkins et al, 2011, Zhou & Mondloch, 2016. Sorting tasks provide a powerful method to explore identity processing for naturally-varying voices, while also allowing for comparisons of familiar and unfamiliar participants' behaviour within the same task.…”

“…Sorting tasks provide a powerful method to explore identity processing for naturally-varying voices, while also allowing for comparisons of familiar and unfamiliar participants' behaviour within the same task. For face perception, sorting tasks have recently been used to probe more nuanced aspects of identity processing: Zhou and Mondloch (2016) report an other-race effect in a face sorting task for unfamiliar but not familiar participants. Redfern and Benton (2017) used a sorting task to investigate the role of facial expressiveness on identity perception using naturally-varying pictures of individuals unknown to the participants: when contrasting high-expressiveness with low-expressiveness faces in two sorting tasks, viewers made significantly more errors for "telling people apart" when sorting highly expressive faces, by mixing pictures of different people into a single perceived identity.…”

Individual differences in human voice pitch are preserved from speech to screams, roars and pain cries

“…There is also preliminary evidence that within each sex, F0 in modal speech correlates with F0 in sung speech [20], and that cues to individual identity are retained in valenced human speech [21], laughter [22], cries [23], and in the screams of both humans ( [24], cf. [25]) and non-human primates [26] (with the caveat that speaker recognition is substantially reduced from these vocalizations compared to modal speech among human listeners [21,22,25]). Finally, longitudinal studies have recently revealed that individual differences in F0 remain relatively stable across the lifespan, from infancy to childhood and throughout adulthood [27,28].…”

Acoustic voice variation within and between speakers

“…Listeners often fail to reliably discriminate between talkers when exposed to voices disguised using falsetto, hyponasality, creaky voice, or whispering (Hirson and Duckworth, 1993;LaRiviere, 1975;Reich and Duke, 1979;Reich et al, 2005;Wagner and Köster, 1999); and changes in a speaker's emotional state substantially impair listeners' abilities to recognize Saslove and Yarmey 1980;cf. Read and Craik 1995) or discriminate among talkers (Lavan et al, 2019). Within-talker variability can also interfere with a listener's ability to judge that samples come from the same (rather than different) talkers.…”