Integrating cues of social interest and voice pitch in men's preferences for women's voices

Influence of male's facial attractiveness, vocal attractiveness and social interest on female's decisions of fairness

The present study employed dictator game and ultimatum game to investigate the effect of facial attractiveness, vocal attractiveness and social interest in expressing positive ("I like you") versus negative signals ("I don't like you") on decision making. Female participants played against male recipients in dictator game and ultimatum game while played against male proposers in ultimatum game. Results showed that participants offered recipients with attractive faces more money than recipients with unattractive faces. Participants also offered recipients with attractive voices more money than recipients with unattractive voices, especially under the positive social interest condition. Moreover, participants allocated more money to recipients who expressed positive social interest than those who expressed negative social interest, whereas they would also expect proposers who expressed positive social interest to offer them more money than proposers who expressed negative social interest. Overall, the results inform beauty premium for faces and voices on opposite-sex economic bargaining. Social interest also affects decision outcomes. However, the beauty premium and effect of social interest varies with participants' roles.

A premium for positive social interest and attractive voices in the acceptability of unfair offers? An ERP study

Although the attractiveness of voices plays an important role in social interactions, it is unclear how voice attractiveness and social interest influence social decision-making. Here, we combined the ultimatum game with recording event-related brain potentials (ERPs) and examined the effect of attractive versus unattractive voices of the proposers, expressing positive versus negative social interest ("I like you" vs. "I don't like you"), on the acceptance of the proposal. Overall, fair offers were accepted at significantly higher rates than unfair offers, and high voice attractiveness increased acceptance rates for all proposals. In ERPs in response to the voices, their attractiveness and expressed social interests yielded early additive effects in the N1 component, followed by interactions in the subsequent P2, P3 and N400 components. More importantly, unfair offers elicited a larger Medial Frontal Negativity (MFN) than fair offers but only when the proposer's voice was unattractive or when the voice carried positive social interest. These results suggest that both voice attractiveness and social interest moderate social decision-making and there is a similar "beauty premium" for voices as for faces.

You are how you speak: The roles of vocal pitch and semantic cues in shaping social perceptions

Social perceptions of speakers are influenced by their voice information, including vocal characteristics and semantic content. Our study investigated how individuals' warmth- and competence-related perceptions of speakers were affected by vocal pitch levels (i.e., high/low) and three kinds of semantic cues (i.e., prosocial, antisocial, and neutral) simultaneously. We have three key findings. First, antisocial cues negatively affected social perceptions, regardless of speakers' gender. However, prosocial cues did not have positive impacts on evaluations of speakers because ratings were similar between prosocial cues and neutral cues. Second, female vocal pitch mattered for warmth-related perceptions but not for competence-related perceptions. The role of semantic cues should be additionally considered when investigating the impact of male vocal pitch on these perceptions. For example, higher-pitched men in prosocial contexts were perceived as warmer, while low-pitched men in antisocial contexts were judged as more competent. Third, the connection between vocal pitch and two kinds of perceptions showed an opposite trend, in which high pitch was related to more warmth but less competence, while the low pitch was associated with less warmth but more competence. These findings extend the understanding of the role of vocal pitch in the formation of stereotypes of strangers in different semantic contexts.

Towards a simultaneously speaking bilingual robot: Primary study on the effect of gender and pitch of the robot's voice

With fast and reliable international transportation, more people with different language backgrounds can interact now. As a result, the need for communicative agents fluent in several languages to assist those people is highlighted. The high cost of hiring human attendants fluent in several languages makes using social robots a more affordable alternative in international gatherings. A social robot capable of presenting a piece of information in more than one language at the same time to its audience is the goal of this line of study. However, the negative effect of background noise on speech comprehension in humans is well-established. Hence, presenting a piece of information in two different languages at the same time by the robot creates an adverse listening condition for both individuals listening to the speech of such a bilingual robot. In this study, we investigated whether manipulating the pitch and gender of the robot's voice could affect human subjects' memory of the presented information in the presence of background noise. The results indicate that the pitch and gender of the speaking voice do indeed affect our memory of the presented information. when a male voice was used, a higher pitch resulted in significantly better memory performance than a lower pitch. Contrarily, when a female voice was used, a lower pitch resulted in significantly better memory in participants than a higher pitch. Both male and female subjects performed significantly better with a female voice in a noisy background. In nutshell, the result of this study suggests using a female voice for robots in noisy conditions, as in the case of simultaneously speaking robots, can significantly improve the retrieval of presented information in human subjects.

Do Voice-Based Judgments of Socially Relevant Speaker Traits Differ Across Speech Types?

PURPOSE

The human voice is a powerful and evolved social tool, with hundreds of studies showing that nonverbal vocal parameters robustly influence listeners' perceptions of socially meaningful speaker traits, ranging from perceived gender and age to attractiveness and trustworthiness. However, these studies have utilized a wide variety of voice stimuli to measure listeners' voice-based judgments of these traits. Here, in the largest scale study known to date, we test whether listeners judge the same unseen speakers differently depending on the complexity of the neutral speech stimulus, from single vowel sounds to a full paragraph.

METHOD

In a playback experiment testing 2,618 listeners, we examine whether commonly studied voice-based judgments of attractiveness, trustworthiness, dominance, likability, femininity/masculinity, and health differ if listeners hear isolated vowels, a series of vowels, single words, single sentences (greeting), counting from 1 to 10, or a full paragraph recited aloud (Rainbow Passage), recorded from the same 208 men and women. Data were collected using a custom-designed interface in which vocalizers and traits were randomly assigned to raters.

RESULTS

Linear-mixed models show that the type of voice stimulus does indeed consistently affect listeners' judgments. Overall, ratings of attractiveness, trustworthiness, dominance, likability, health, masculinity among men, and femininity among women increase as speech duration increases. At the same time, speaker-level regression analyses show that interindividual differences in perceived speaker traits are largely preserved across voice stimuli, especially among those of a similar duration.

CONCLUSIONS

Socially relevant perceptions of speakers are not wholly changed but rather moderated by the length of their speech. Indeed, the same vocalizer is perceived in a similar way regardless of which neutral statements they speak, with the caveat that longer utterances explain the most shared variance in listeners' judgments and elicit the highest ratings on all traits, possibly by providing additional nonverbal information to listeners.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21158890.

Hearing, touching, and multisensory integration during mate choice

Mate choice is a potent generator of diversity and a fundamental pillar for sexual selection and evolution. Mate choice is a multistage affair, where complex sensory information and elaborate actions are used to identify, scrutinize, and evaluate potential mating partners. While widely accepted that communication during mate assessment relies on multimodal cues, most studies investigating the mechanisms controlling this fundamental behavior have restricted their focus to the dominant sensory modality used by the species under examination, such as vision in humans and smell in rodents. However, despite their undeniable importance for the initial recognition, attraction, and approach towards a potential mate, other modalities gain relevance as the interaction progresses, amongst which are touch and audition. In this review, we will: (1) focus on recent findings of how touch and audition can contribute to the evaluation and choice of mating partners, and (2) outline our current knowledge regarding the neuronal circuits processing touch and audition (amongst others) in the context of mate choice and ask (3) how these neural circuits are connected to areas that have been studied in the light of multisensory integration.

Vocal modulation in human mating and competition

The human voice is dynamic, and people modulate their voices across different social interactions. This article presents a review of the literature examining natural vocal modulation in social contexts relevant to human mating and intrasexual competition. Altering acoustic parameters during speech, particularly pitch, in response to mating and competitive contexts can influence social perception and indicate certain qualities of the speaker. For instance, a lowered voice pitch is often used to exert dominance, display status and compete with rivals. Changes in voice can also serve as a salient medium for signalling a person's attraction to another, and there is evidence to support the notion that attraction and/or romantic interest can be distinguished through vocal tones alone. Individuals can purposely change their vocal behaviour in attempt to sound more attractive and to facilitate courtship success. Several findings also point to the effectiveness of vocal change as a mechanism for communicating relationship status. As future studies continue to explore vocal modulation in the arena of human mating, we will gain a better understanding of how and why vocal modulation varies across social contexts and its impact on receiver psychology. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.

Contextualising courtship: Exploring male body odour effects on vocal modulation

Voice characteristics are important to communicate socially relevant information. Recent research has shown that individuals alter their voices depending on the context of social interactions and perceived characteristics of the audience, and this affects how they are perceived. Numerous studies have also shown that the presence of bodily odours can elicit psychological changes in people. Here, we tested whether the presence of male axillary odour would influence vocal modulations in courtship contexts. We analysed differences in vocal parameters and attractiveness ratings across 950 recordings from 80 participants as they responded to opposite-sex target stimuli. Using these, we tested whether men's and women's vocal parameters and perceived stimuli attractiveness differed in the presence or absence of the odour. We expected women to speak with increased voice F₀, and men to lower their pitch, when exposed to male body odour, especially if it were of high quality. However, neither the presence of male odour, its quality, nor the addition of androstadienone produced any consistent changes in vocal parameters. Nevertheless, rated stimulus attractiveness was predicted by F₀ and especially F₀ variability, suggesting that this is a key parameter in signalling attraction during human courtship, and supporting the idea that vocal modulations are context-sensitive.

Examining vocal attractiveness through articulatory working space

Robust gender differences exist in the acoustic correlates of clearly articulated speech, with females, on average, producing speech that is acoustically and phonetically more distinct than that of males. This study investigates the relationship between several acoustic correlates of clear speech and subjective ratings of vocal attractiveness. Talkers were recorded producing vowels in /bVd/ context and sentences containing the four corner vowels. Multiple measures of working vowel space were computed from continuously sampled formant trajectories and were combined with measures of speech timing known to co-vary with clear articulation. Partial least squares regression (PLS-R) modeling was used to predict ratings of vocal attractiveness for male and female talkers based on the acoustic measures. PLS components that loaded on size and shape measures of working vowel space-including the quadrilateral vowel space area, convex hull area, and bivariate spread of formants-along with measures of speech timing were highly successful at predicting attractiveness in female talkers producing /bVd/ words. These findings are consistent with a number of hypotheses regarding human attractiveness judgments, including the role of sexual dimorphism in mate selection, the significance of traits signalling underlying health, and perceptual fluency accounts of preferences.

Gender context modulation on the self-enhancement effect of vocal attractiveness evaluation

People evaluated their own voices as sounding more attractive than others rated their voices (i.e., self-enhancement effect from the perspective of the rater, termed "SE_rater"), and people also rated their own voices as more attractive than the voices of others (i.e., self-enhancement effect from the perspective of the voice, termed "SE_voice"). The aim of the present study is to explore whether the gender context (i.e., same-sex and opposite-sex rating context) could influence the SE effect of voice attractiveness evaluation. Male and female participants were asked to rate the attractiveness of their own voices and other participants' voices, either in a same-sex session or an opposite-sex session. The results demonstrated both the SE_rater and SE_voice effect in the same-sex and opposite-sex contexts, for both male and female. More importantly, we found that the SE_rater for the male voices was significantly greater than that for the female voices in the same-sex context whereas no such difference was found in the opposite-sex context. In addition, the SE_voice effect in men was larger in the same-sex context than that in the opposite-sex context whereas the SE_voice in women was smaller in the same-sex context than that in the opposite-sex context. These findings indicated that the self-enhancement effect of vocal attractiveness was modulated by the gender context.

Content matters: Cyclic effects on women's voices depend on social context

Women's voices reportedly sound more attractive during the fertile days compared to the non-fertile days of their menstrual cycle. Here we investigated whether the speech content modulates the cyclic changes in women's voices. We asked 72 men and women to rate how interested they were in getting to know the speaker based on her voice. Forty-two naturally cycling women were recorded once during the late follicular phase (high fertility) and once during the luteal phase (low fertility) while speaking sentences of neutral and social content. Listeners were more interested in getting to know the speakers when hearing sentences with social content. Furthermore, raters were more interested in getting to know the speakers when these were recorded in the late follicular than in the luteal phase, but only in sentences with social content. Notably, levels of reproductive hormones (EP ratio) across the cycle phases did not significantly predict the preference for late follicular voices, but echoing the perceptual ratings, there was a significant EP ratio x speech content interaction. Phonetic analyses of mean fundamental frequency (F0) revealed a main effect of menstrual cycle phase and speech content but no interaction. Employing an action-oriented task, the present study extends findings of cycle-dependent voice changes by emphasising that speech content critically modulates fertility effects.

Human voice attractiveness processing: Electrophysiological evidence

Voice attractiveness plays a significant role in social interaction and mate choice. However, how listeners perceive attractive voices and whether this process is mandatory, is poorly understood. The current study explores this question using event-related brain potentials. Participants listened to syllables spoken by male and female voices with high or low attractiveness while completing an implicit (voice un-related) tone detection task or explicitly judging voice attractiveness. In both tasks, attractive male voices elicited a larger N1 than unattractive voices. However, an effect of voice attractiveness on the late positive complex (LPC) was only seen in the explicit task but it was present to both same- and opposite-sex voices. Taken together, voice attractiveness processing during early stages appears to be rapid and mandatory and related to mate selection, whereas during later elaborated processing, voice attractiveness is strategic and aesthetics-based, requiring attentional resources.

High voice pitch mitigates the aversiveness of antisocial cues in men's speech

Speech contains both explicit social information in semantic content and implicit cues to social behaviour and mate quality in voice pitch. Voice pitch has been demonstrated to have pervasive effects on social perceptions, but few studies have examined these perceptions in the context of meaningful speech. Here, we examined whether male voice pitch interacted with socially relevant cues in speech to influence listeners' perceptions of trustworthiness and attractiveness. We artificially manipulated men's voices to be higher and lower in pitch when speaking words that were either prosocial or antisocial in nature. In Study 1, we found that listeners perceived lower-pitched voices as more trustworthy and attractive in the context of prosocial words than in the context of antisocial words. In Study 2, we found evidence that suggests this effect was driven by stronger preferences for higher-pitched voices in the context of antisocial cues, as voice pitch preferences were not significantly different in the context of prosocial cues. These findings suggest that higher male voice pitch may ameliorate the negative effects of antisocial speech content and that listeners may be particularly avoidant of those who express multiple cues to antisociality across modalities.

The Perception of Operational Sex Ratios by Voice

Adult sex ratios in a local environment are linked to a wide variety of reproductive behaviors in humans and other animals. When sex ratios are biased, the more numerous sex faces increased competition for mates and is more likely to yield to the sociosexual preferences of the less numerous sex. Despite widespread evidence of the relationship between sex ratios and behavior, we know little about whether or how sex ratios are encoded and perceived. In two experiments men and women showed perceived sex ratios that correlated with actual sex ratios after 1500 ms exposures to groups of simultaneous voices. However, men perceived more female voices than women did, and women perceived more male voices than men did. Women showed better accuracy than men, but only when sex ratios departed markedly from 50%. Increasing the number of simultaneous voices reduced accuracy, but only at extreme sex ratios. Talker age also significantly affected perceived sex ratios, suggesting that perceived operational sex ratios are adaptively linked to the reproductive viability of the local population. The results suggest that listeners automatically encode vocal sex ratio information and that perceived sex ratios are influenced by characteristics of the local population and characteristics of the listener.

Low Vocal Pitch Preference Drives First Impressions Irrespective of Context in Male Voices but Not in Female Voices

Vocal pitch has been found to influence judgments of perceived trustworthiness and dominance from a novel voice. However, the majority of findings arise from using only male voices and in context-specific scenarios. In two experiments, we first explore the influence of average vocal pitch on first-impression judgments of perceived trustworthiness and dominance, before establishing the existence of an overall preference for high or low pitch across genders. In Experiment 1, pairs of high- and low-pitched temporally reversed recordings of male and female vocal utterances were presented in a two-alternative forced-choice task. Results revealed a tendency to select the low-pitched voice over the high-pitched voice as more trustworthy, for both genders, and more dominant, for male voices only. Experiment 2 tested an overall preference for low-pitched voices, and whether judgments were modulated by speech content, using forward and reversed speech to manipulate context. Results revealed an overall preference for low pitch, irrespective of direction of speech, in male voices only. No such overall preference was found for female voices. We propose that an overall preference for low pitch is a default prior in male voices irrespective of context, whereas pitch preferences in female voices are more context- and situation-dependent. The present study confirms the important role of vocal pitch in the formation of first-impression personality judgments and advances understanding of the impact of context on pitch preferences across genders.

Vocal fundamental and formant frequencies affect perceptions of speaker cooperativeness

In recent years, the perception of social traits in faces and voices has received much attention. Facial and vocal masculinity are linked to perceptions of trustworthiness; however, while feminine faces are generally considered to be trustworthy, vocal trustworthiness is associated with masculinized vocal features. Vocal traits such as pitch and formants have previously been associated with perceived social traits such as trustworthiness and dominance, but the link between these measurements and perceptions of cooperativeness have yet to be examined. In Experiment 1, cooperativeness ratings of male and female voices were examined against four vocal measurements: fundamental frequency (F0), pitch variation (F0-SD), formant dispersion (Df), and formant position (Pf). Feminine pitch traits (F0 and F0-SD) and masculine formant traits (Df and Pf) were associated with higher cooperativeness ratings. In Experiment 2, manipulated voices with feminized F0 were found to be more cooperative than voices with masculinized F0(,) among both male and female speakers, confirming our results from Experiment 1. Feminine pitch qualities may indicate an individual who is friendly and non-threatening, while masculine formant qualities may reflect an individual that is socially dominant or prestigious, and the perception of these associated traits may influence the perceived cooperativeness of the speakers.

Vote Choice, Ideology, and Social Dominance Orientation Influence Preferences for Lower Pitched Voices in Political Candidates

Humans are equipped with a psychological system of followership that evolved to regulate choices of leaders based partly on would-be leaders' physiological features. One such feature is voice pitch, which is determined by the physiology of the throat. Recent studies find that political candidates in modern elections with lower-pitched voices are generally more successful. As lower-pitched voices are perceived as stronger and more dominant, these findings have been taken to indicate a general preference for dispositional abilities in leaders to protect and prevail in conflicts. Here we extend upon these findings by demonstrating that conservatives and Republicans tend to view the world as much more competitive and threatening than liberals and Democrats. We utilize two existing data sources to show that political candidates with lower-pitched voices are preferred more among conservative Republicans than among liberal Democrats. In a third study we show that preferences for lower-pitched candidate voices stem from individual differences in Social Dominance Orientation (SDO). Importantly, across all three studies subjects' party affiliation, ideology, and SDO only predict preferences for male candidate voices. We conclude with a discussion of the results in relation to followership psychology and general debates on the rationality of the public with respect to elections.

Perceptions of Competence, Strength, and Age Influence Voters to Select Leaders with Lower-Pitched Voices

Voters prefer leaders with lower-pitched voices because they are perceived as stronger, having greater physical prowess, more competent, and having greater integrity. An alternative hypothesis that has yet to be tested is that lower-pitched voices are perceived as older and thus wiser and more experienced. Here the relationships between candidate voice pitch, candidate age, and electoral success are examined with two experiments. Study 1 tests whether voters discriminate on candidate age. The results show that male and female candidates in their 40s and 50s, the time in the lifecycle when voice pitch is at its lowest, are preferred over candidates in their 30s, 60s, and 70s. Study 2 shows that the preference for leaders with lower-pitched voices correlates with the perception that speakers with lower voices are stronger, more competent, and older, but the influence of perception of age on vote choice is the weakest of the three.

Social Responses to Conversational TV VUI

The study investigated whether apologetic synthetic gendered voices affect users' perception of an error-prone VUI. In a TV viewing task, participants interacted with the conversational TV, and executed eight menus in a 2 (apologetic error message: yes vs. no) by 2 (voice gender) by 2 (subject gender) gender balanced, between participants experiment. When participants encountered errors, the TV provided verbal error messages, with or without an apology. The results revealed significant two-way interaction effects of apology (yes) and voice gender (male) on perception of the TV, and the voice. Irrespective of gender, participants responded to a male voice more, when it offered apologies for errors. It is interpreted that the context in which genuineness of apology was regarded as important made participants perceive a male voice as being more trustworthy than a female voice. The participants seem to have applied gender stereotypical perceptions to gendered VUI, as they do to other humans.

More than just two sexes: the neural correlates of voice gender perception in gender dysphoria

Gender dysphoria (also known as “transsexualism”) is characterized as a discrepancy between anatomical sex and gender identity. Research points towards neurobiological influences. Due to the sexually dimorphic characteristics of the human voice, voice gender perception provides a biologically relevant function, e.g. in the context of mating selection. There is evidence for a better recognition of voices of the opposite sex and a differentiation of the sexes in its underlying functional cerebral correlates, namely the prefrontal and middle temporal areas. This fMRI study investigated the neural correlates of voice gender perception in 32 male-to-female gender dysphoric individuals (MtFs) compared to 20 non-gender dysphoric men and 19 non-gender dysphoric women. Participants indicated the sex of 240 voice stimuli modified in semitone steps in the direction to the other gender. Compared to men and women, MtFs showed differences in a neural network including the medial prefrontal gyrus, the insula, and the precuneus when responding to male vs. female voices. With increased voice morphing men recruited more prefrontal areas compared to women and MtFs, while MtFs revealed a pattern more similar to women. On a behavioral and neuronal level, our results support the feeling of MtFs reporting they cannot identify with their assigned sex.

Vocal fry may undermine the success of young women in the labor market

Vocal fry is speech that is low pitched and creaky sounding, and is increasingly common among young American females. Some argue that vocal fry enhances speaker labor market perceptions while others argue that vocal fry is perceived negatively and can damage job prospects. In a large national sample of American adults we find that vocal fry is interpreted negatively. Relative to a normal speaking voice, young adult female voices exhibiting vocal fry are perceived as less competent, less educated, less trustworthy, less attractive, and less hirable. The negative perceptions of vocal fry are stronger for female voices relative to male voices. These results suggest that young American females should avoid using vocal fry speech in order to maximize labor market opportunities.

Men's preferences for women's femininity in dynamic cross-modal stimuli

Men generally prefer feminine women's faces and voices over masculine women's faces and voices, and these cross-modal preferences are positively correlated. Men's preferences for female facial and vocal femininity have typically been investigated independently by presenting soundless still images separately from audio-only vocal recordings. For the first time ever, we presented men with short video clips in which dynamic faces and voices were simultaneously manipulated in femininity/masculinity. Men preferred feminine men's faces over masculine men's faces, and preferred masculine men's voices over feminine men's voices. We found that men preferred feminine women's faces and voices over masculine women's faces and voices. Men's attractiveness ratings of both feminine and masculine faces were increased by the addition of vocal femininity. Also, men's attractiveness ratings of feminine and masculine voices were increased by the addition of facial femininity present in the video. Men's preferences for vocal and facial femininity were significantly and positively correlated when stimuli were female, but not when they were male. Our findings complement other evidence for cross-modal femininity preferences among male raters, and show that preferences observed in studies using still images and/or independently presented vocal stimuli are also observed when dynamic faces and voices are displayed simultaneously in video format.

Sex matters: Neural correlates of voice gender perception

The basis for different neural activations in response to male and female voices as well as the question, whether men and women perceive male and female voices differently, has not been thoroughly investigated. Therefore, the aim of the present study was to examine the behavioral and neural correlates of gender-related voice perception in healthy male and female volunteers. fMRI data were collected while 39 participants (19 female) were asked to indicate the gender of 240 voice stimuli. These stimuli included recordings of 3-syllable nouns as well as the same recordings pitch-shifted in 2, 4 and 6 semitone steps in the direction of the other gender. Data analysis revealed a) equal voice discrimination sensitivity in men and women but better performance in the categorization of opposite-sex stimuli at least in men, b) increased responses to increasing gender ambiguity in the mid cingulate cortex and bilateral inferior frontal gyri, and c) stronger activation in a fronto-temporal neural network in response to voices of the opposite sex. Our results indicate a gender specific processing for male and female voices on a behavioral and neuronal level. We suggest that our results reflect higher sensitivity probably due to the evolutionary relevance of voice perception in mate selection.

Facial visualizations of women's voices suggest a cross-modality preference for femininity

Women with higher-pitched voices and more feminine facial features are commonly judged as being more attractive than are women with lower-pitched voices and less feminine faces, possibly because both features are affected by (age-related) variations in endocrine status. These results are primarily derived from investigations of perceptions of variations in single-modality stimuli (i.e., faces or voices) in samples of young adult women. In the present study we sought to test whether male and female perceptions of women's voices affect visual representations of facial femininity. Eighty men and women judged voice recordings of 10 young girls (11-15 years), 10 adult women (19-28 years) and 10 peri-/post-menopausal women (50-64 years) on age, attractiveness, and femininity. Another 80 men and women were asked to indicate the face they think each voice corresponded to using a video that gradually changed from a masculine looking male face into a feminine looking female face. Both male and female participants perceived voices of young girls and adult women to be significantly younger, more attractive and feminine than those of peri-/post-menopausal women. Hearing young girls' and adult women's voices resulted in both men and women selecting faces that differed markedly in apparent femininity from those associated with peri-/post-menopausal women's voices. Voices of young girls had the strongest effect on visualizations of facial femininity. Our results suggest a cross-modal preference for women's vocal and facial femininity, which depends on female age and is independent of the perceiver's sex.

Facial visualizations of women's voices suggest a cross-modality preference for femininity

Women with higher-pitched voices and more feminine facial features are commonly judged as being more attractive than are women with lower-pitched voices and less feminine faces, possibly because both features are affected by (age-related) variations in endocrine status. These results are primarily derived from investigations of perceptions of variations in single-modality stimuli (i.e., faces or voices) in samples of young adult women. In the present study we sought to test whether male and female perceptions of women's voices affect visual representations of facial femininity. Eighty men and women judged voice recordings of 10 young girls (11-15 years), 10 adult women (19-28 years) and 10 peri-/post-menopausal women (50-64 years) on age, attractiveness, and femininity. Another 80 men and women were asked to indicate the face they think each voice corresponded to using a video that gradually changed from a masculine looking male face into a feminine looking female face. Both male and female participants perceived voices of young girls and adult women to be significantly younger, more attractive and feminine than those of peri-/post-menopausal women. Hearing young girls' and adult women's voices resulted in both men and women selecting faces that differed markedly in apparent femininity from those associated with peri-/post-menopausal women's voices. Voices of young girls had the strongest effect on visualizations of facial femininity. Our results suggest a cross-modal preference for women's vocal and facial femininity, which depends on female age and is independent of the perceiver's sex.

Preference for leaders with masculine voices holds in the case of feminine leadership roles

Human voice pitch research has focused on perceptions of attractiveness, strength, and social dominance. Here we examine the influence of pitch on selection of leaders, and whether this influence varies by leadership role. Male and female leaders with lower-pitched (i.e., masculine) voices are generally preferred by both men and women. We asked whether this preference shifts to favor higher-pitch (i.e., feminine) voices within the specific context of leadership positions that are typically held by women (i.e., feminine leadership roles). In hypothetical elections for two such positions, men and women listened to pairs of male and female voices that differed only in pitch, and were asked which of each pair they would vote for. As in previous studies, men and women preferred female candidates with masculine voices. Likewise, men preferred men with masculine voices. Women, however, did not discriminate between male voices. Overall, contrary to research showing that perceptions of voice pitch can be influenced by social context, these results suggest that the influence of voice pitch on perceptions of leadership capacity is largely consistent across different domains of leadership.

Voice and handgrip strength predict reproductive success in a group of indigenous African females

Evolutionary accounts of human traits are often based on proxies for genetic fitness (e.g., number of sex partners, facial attractiveness). Instead of using proxies, actual differences in reproductive success is a more direct measure of darwinian fitness. Certain voice acoustics such as fundamental frequency and measures of health such as handgrip strength correlate with proxies of fitness, yet there are few studies showing the relation of these traits to reproduction. Here, we explore whether the fundamental frequency of the voice and handgrip strength account for differences in actual reproduction among a population of natural fertility humans. Our results show that both fundamental frequency and handgrip strength predict several measures of reproductive success among a group of indigenous Namibian females, particularly amongst the elderly, with weight also predicting reproductive outcomes among males. These findings demonstrate that both hormonally regulated and phenotypic quality markers can be used as measures of darwinian fitness among humans living under conditions that resemble the evolutionary environment of Homo sapiens. We also argue that these findings provide support for the Grandmother Hypothesis.

Sounds like a winner: voice pitch influences perception of leadership capacity in both men and women

It is well known that non-human animals respond to information encoded in vocal signals, and the same can be said of humans. Specifically, human voice pitch affects how speakers are perceived. As such, does voice pitch affect how we perceive and select our leaders? To answer this question, we recorded men and women saying 'I urge you to vote for me this November'. Each recording was manipulated digitally to yield a higher- and lower-pitched version of the original. We then asked men and women to vote for either the lower- or higher-pitched version of each voice. Our results show that both men and women select male and female leaders with lower voices. These findings suggest that men and women with lower-pitched voices may be more successful in obtaining positions of leadership. This might also suggest that because women, on average, have higher-pitched voices than men, voice pitch could be a factor that contributes to fewer women holding leadership roles than men. Additionally, while people are free to choose their leaders, these results clearly demonstrate that these choices cannot be understood in isolation from biological influences.

Preferences for very low and very high voice pitch in humans

Manipulations of voice pitch have been shown to alter attractiveness ratings, but whether preferences extend to very low or very high voice pitch is unknown. Here, we manipulated voice pitch in averaged men's and women's voices by 2 Hz intervals to create a range of male and female voices speaking monopthong vowel sounds and spanning a range of frequencies from normal to very low and very high pitch. With these voices, we used the method of constant stimuli to measure preferences for voice. Nineteen university students (ages: 20–25) participated in three experiments. On average, men preferred high-pitched women's voices to low-pitched women's voices across all frequencies tested. On average, women preferred men's voices lowered in pitch, but did not prefer very low men's voices. The results of this study may reflect selection pressures for men's and women's voices, and shed light on a perceptual link between voice pitch and vocal attractiveness.

Sexual selection on human faces and voices

Humans are highly sexually dimorphic primates, and some of the most conspicuous human sex differences occur in the face and voice. Consequently, this article utilizes research findings on human faces and voices to illustrate how human sex differences may have arisen by sexual selection (i.e., the type of natural selection favoring traits that increase mating opportunities). Evidence suggesting that sexual selection shaped women's faces and voices is reviewed. However, sexual selection likely operated more strongly on men over human evolution. Thus, this research focuses on two types of sexual selection operating on men: female mate choice, which favors traits that attract females, and male contests, which favor traits for excluding competitors from mates by force or threat of force. This article demonstrates how masculine faces and voices advertize critical information about men's mate value and threat potential, and reviews evidence that women's preferences and men's deference to masculine faces and voices reflect this information content. Data suggesting that facial and vocal masculinity influences men's mating opportunities and reproduction are discussed, and the article concludes by highlighting directions for future research.

Voice pitch influences perceptions of sexual infidelity

Sexual infidelity can be costly to members of both the extra-pair and the paired couple. Thus, detecting infidelity risk is potentially adaptive if it aids in avoiding cuckoldry or loss of parental and relationship investment. Among men, testosterone is inversely related to voice pitch, relationship and offspring investment, and is positively related to the pursuit of short-term relationships, including extra-pair sex. Among women, estrogen is positively related to voice pitch, attractiveness, and the likelihood of extra-pair involvement. Although prior work has demonstrated a positive relationship between men's testosterone levels and infidelity, this study is the first to investigate attributions of infidelity as a function of sexual dimorphism in male and female voices. We found that men attributed high infidelity risk to feminized women's voices, but not significantly more often than did women. Women attributed high infidelity risk to masculinized men's voices at significantly higher rates than did men. These data suggest that voice pitch is used as an indicator of sexual strategy in addition to underlying mate value. The aforementioned attributions may be adaptive if they prevent cuckoldry and/or loss of parental and relationship investment via avoidance of partners who may be more likely to be unfaithful.

Voice Pitch Influences Perceptions of Sexual Infidelity

Sexual infidelity can be costly to members of both the extra-pair and the paired couple. Thus, detecting infidelity risk is potentially adaptive if it aids in avoiding cuckoldry or loss of parental and relationship investment. Among men, testosterone is inversely related to voice pitch, relationship and offspring investment, and is positively related to the pursuit of short-term relationships, including extra-pair sex. Among women, estrogen is positively related to voice pitch, attractiveness, and the likelihood of extra-pair involvement. Although prior work has demonstrated a positive relationship between men's testosterone levels and infidelity, this study is the first to investigate attributions of infidelity as a function of sexual dimorphism in male and female voices. We found that men attributed high infidelity risk to feminized women's voices, but not significantly more often than did women. Women attributed high infidelity risk to masculinized men's voices at significantly higher rates than did men. These data suggest that voice pitch is used as an indicator of sexual strategy in addition to underlying mate value. The aforementioned attributions may be adaptive if they prevent cuckoldry and/or loss of parental and relationship investment via avoidance of partners who may be more likely to be unfaithful.