Facial attractiveness has been linked to the averageness (or typicality) of a face. More tentatively, it has also been linked to a speaker’s vocal attractiveness, via the “honest signal” hypothesis, holding that attractiveness signals good genes. In four experiments, we assessed ratings for attractiveness and two common measures of distinctiveness (“distinctiveness-in-thecrowd”- DITC and “deviation-based distinctiveness”-DEV) for faces and voices (vowels or sentences) from 64 young adult speakers (32 female). Consistent and strong negative correlations between attractiveness and DEV generally supported the averageness account of attractiveness for both voices and faces. By contrast, indicating that both measures of distinctiveness reflect different constructs, correlations between attractiveness and DITC were numerically positive for faces (though small and non-significant), and significant for voices in sentence stimuli. As the only exception, voice ratings based on vowels exhibited a moderate but significant negative correlation between attractiveness and DITC. Between faces and voices, distinctiveness ratings were uncorrelated. Remarkably, and at variance with the honest signal hypothesis, vocal and facial attractiveness were uncorrelated, with the exception of a moderatepositive correlation for vowels. Overall, while our findings strongly support an averageness account of attractiveness for both domains, they provide little evidence for an honest signal account of facial and vocal attractiveness in complex naturalistic speech. Although our findings for vowels do not rule out the tentative notion that more primitive vocalizations can provide relevant clues to genetic fitness, researchers should carefully consider the nature of voice samples, and the degree to which these are representative of human vocal communication.

Although previous research demonstrated perceptual aftereffects in emotional voice adaptation, the contribution of different vocal cues to these effects is unclear. In two experiments, we used parameter-specific morphing of adaptor voices to investigate the relative roles of fundamental frequency (F0) and timbre in vocal emotion adaptation, using angry and fearful utterances. Participants adapted to voices containing emotion-specific information in either F0 or timbre, with all other parameters kept constant at an intermediate 50% morph level. Full emotional adaptors and ambiguous adaptors were used as reference conditions. Adaptors were either of the same (Experiment 1) or opposite speaker gender (Experiment 2) of target voices. In Experiment 1, we found consistent aftereffects in all adaptation conditions. Crucially, aftereffects following timbre adaptors were much larger than following F0 adaptors and were only marginally smaller than those following full adaptors. In Experiment 2, adaptation aftereffects appeared massively and proportionally reduced, with differences between morph types being no longer significant. These results suggest that timbre plays a larger role than F0 in vocal emotion adaptation, and that vocal emotion adaptation is compromised by eliminating gender-congruency between adaptors and targets. Our findings also add to mounting evidence suggesting a major role of timbre in auditory adaptation.

Purpose: Using naturalistic synthesized speech, we determined the relative importance of acoustic cues in voice gender and, for the first time, vocal age perception in Cochlear Implant (CI) users.Method: We investigated 28 CI users’ abilities to utilize fundamental frequency (F0) and timbre in perceiving voice gender (Experiment 1) and additional timing cues in perceiving vocal age (Experiment 2). TANDEM-STRAIGHT-based parameter-specific voice morphing was used to control acoustics in voice stimuli. Individual differences in CI users’ performance were captured by quantifying deviations from a control group of 19 normal hearing (NH) listeners. Results: CI users’ gender perception seemed exclusively based on F0, whereas the NH listeners efficiently used timbre. For age perception, timbre was more informative than F0 for both groups, with minor contributions of temporal cues. While a few CI users performed comparable to NH listeners overall, others were at chance. Separate analyses confirmed that even in high performing CI users, gender perception was almost exclusively based on F0. While high performers could discriminate age in male and female voices, low performers were close to chance overall, but used F0 as misleading cue to age (classifying female voices as young and male voices as old). Satisfaction with CI generally correlated with performance.Conclusions: We confirmed that CI user gender classification bases mainly on F0, but high performers could make reasonable usage of TIMBRE cues in both gender and age perception. Overall, parameter-specific morphing is a promising approach to objectively assess individual profiles of CI users abilities to perceive nonverbal social-communicative vocal signals.