How does familiarity with a voice affect trait judgements?

Algorithmic voice transformations reveal the phonological basis of language-familiarity effects in cross-cultural emotion judgments

People have a well-described advantage in identifying individuals and emotions in their own culture, a phenomenon also known as the other-race and language-familiarity effect. However, it is unclear whether native-language advantages arise from genuinely enhanced capacities to extract relevant cues in familiar speech or, more simply, from cultural differences in emotional expressions. Here, to rule out production differences, we use algorithmic voice transformations to create French and Japanese stimulus pairs that differed by exactly the same acoustical characteristics. In two cross-cultural experiments, participants performed better in their native language when categorizing vocal emotional cues and detecting non-emotional pitch changes. This advantage persisted over three types of stimulus degradation (jabberwocky, shuffled and reversed sentences), which disturbed semantics, syntax, and supra-segmental patterns, respectively. These results provide evidence that production differences are not the sole drivers of the language-familiarity effect in cross-cultural emotion perception. Listeners' unfamiliarity with the phonology of another language, rather than with its syntax or semantics, impairs the detection of pitch prosodic cues and, in turn, the recognition of expressive prosody.

The effect of familiarity on within-person age judgements from voices

Listeners can perceive a person's age from their voice with above chance accuracy. Studies have usually established this by asking listeners to directly estimate the age of unfamiliar voices. The recordings used mostly include cross-sectional samples of voices, including people of different ages to cover the age range of interest. Such cross-sectional samples likely include not only cues to age in the sound of the voice but also socio-phonetic cues, encoded in how a person speaks. How age perpcetion accuracy is affected when minimizing socio-phonetic cues by sampling the same voice at different time points remains largely unknown. Similarly, with the voices in age perception studies being usually unfamiliar to listeners, it is unclear how familiarity with a voice affects age perception. We asked listeners who were either familiar or unfamiliar with a set of four voices to complete an age discrimination task: listeners heard two recordings of the same person's voice, recorded 15 years apart, and were asked to indicate in which recording the person was younger. Accuracy for both familiar and unfamiliar listeners was above chance. While familiarity advantages were apparent, accuracy was not particularly high: familiar and unfamiliar listeners were correct for 68.2% and 62.7% of trials, respectively (chance = 50%). Familiarity furthermore interacted with the voices included. Overall, our findings indicate that age perception from voices is not a trivial task at all times - even when listeners are familiar with a voice. We discuss our findings in the light of how reliable voice may be as a signal for age.

Instrumental learning in social interactions: Trait learning from faces and voices

Recent research suggests that reinforcement learning may underlie trait formation in social interactions with faces. The current study investigated whether the same learning mechanisms could be engaged for trait learning from voices. On each trial of a training phase, participants (N = 192) chose from pairs of human or slot machine targets that varied in the (1) reward value and (2) generosity of their payouts. Targets were either auditory (voices or tones; Experiment 1) or visual (faces or icons; Experiment 2) and were presented sequentially before payout feedback. A test phase measured participant choice behaviour, and a post-test recorded their target preference ratings. For auditory targets, we found a significant effect of reward only on target choices, but saw higher preference ratings for more generous humans and slot machines. For visual targets, findings from previous studies were replicated: participants learned about both generosity and reward, but generosity was prioritised in the human condition. These findings provide one of the first demonstrations of reinforcement learning of reward with auditory stimuli in a social learning task, but suggest that the use of auditory targets does alter learning in this paradigm. Conversely, reinforcement learning of reward and trait information with visual stimuli remains intact even when sequential presentation introduces a delay in feedback.