Voice-based judgments of sex, height, weight, attractiveness, health, and psychological traits based on free speech versus scripted speech.

How do we perceive others based on their voices? This question has attracted research and media attention for decades, producing hundreds of studies showing that the voice is socially and biologically relevant, but these studies vary in methodology and ecological validity. Here we test whether vocalizers producing read versus free speech are judged similarly by listeners on ten biological and/or psychosocial traits. In perception experiments using speech from 208 men and women and ratings from 4,088 listeners, we show that listeners' assessments of vocalizer sex and age are highly accurate, regardless of speech type. Assessments of body size, femininity-masculinity and women's health also did not differ between free and read speech. In contrast, read speech elicited higher ratings of attractiveness, dominance and trustworthiness in both sexes and of health in males compared to free speech. Importantly, these differences were small, and we additionally show moderate to strong correlations between ratings of the same vocalizers based on their read and free speech for all ten traits, indicating that voice-based judgments are highly consistent within speakers, whether or not speech is spontaneous. Our results provide evidence that the human voice can communicate various biological and psychosocial traits via both read and free speech, with theoretical and practical implications.

Comparing accuracy in voice-based assessments of biological speaker traits across speech types.

Nonverbal acoustic parameters of the human voice provide cues to a vocaliser's sex, age, and body size that are relevant in human social and sexual communication, and also increasingly so for computer-based voice recognition and synthesis technologies. While studies have shown some capacity in human listeners to gauge these biological traits from unseen speakers, it remains unknown whether speech complexity improves accuracy. Here, in over 200 vocalisers and 1500 listeners of both sexes, we test whether voice-based assessments of sex, age, height and weight vary from isolated vowels and words, to sequences of vowels and words, to full sentences or paragraphs. We show that while listeners judge sex and especially age more accurately as speech complexity increases, accuracy remains high across speech types, even for a single vowel sound. In contrast, the actual heights and weights of vocalisers explain comparatively less variance in listener's assessments of body size, which do not vary systematically by speech type. Our results thus show that while more complex speech can improve listeners' biological assessments, the gain is ecologically small, as listeners already show an impressive capacity to gauge speaker traits from extremely short bouts of standardised speech, likely owing to within-speaker stability in underlying nonverbal vocal parameters such as voice pitch. We discuss the methodological, technological, and social implications of these results.

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.

Predicting strength from aggressive vocalizations versus speech in African bushland and urban communities.

The human voice carries information about a vocalizer's physical strength that listeners can perceive and that may influence mate choice and intrasexual competition. Yet, reliable acoustic correlates of strength in human speech remain unclear. Compared to speech, aggressive nonverbal vocalizations (roars) may function to maximize perceived strength, suggesting that their acoustic structure has been selected to communicate formidability, similar to the vocal threat displays of other animals. Here, we test this prediction in two non-WEIRD African samples: an urban community of Cameroonians and rural nomadic Hadza hunter-gatherers in the Tanzanian bushlands. Participants produced standardized speech and volitional roars and provided handgrip strength measures. Using acoustic analysis and information-theoretic multi-model inference and averaging techniques, we show that strength can be measured from both speech and roars, and as predicted, strength is more reliably gauged from roars than vowels, words or greetings. The acoustic structure of roars explains 40-70% of the variance in actual strength within adults of either sex. However, strength is predicted by multiple acoustic parameters whose combinations vary by sex, sample and vocal type. Thus, while roars may maximally signal strength, more research is needed to uncover consistent and likely interacting acoustic correlates of strength in the human voice. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.

Human voice pitch measures are robust across a variety of speech recordings: methodological and theoretical implications.

Fundamental frequency (fo), perceived as voice pitch, is the most sexually dimorphic, perceptually salient and intensively studied voice parameter in human nonverbal communication. Thousands of studies have linked human fo to biological and social speaker traits and life outcomes, from reproductive to economic. Critically, researchers have used myriad speech stimuli to measure fo and infer its functional relevance, from individual vowels to longer bouts of spontaneous speech. Here, we acoustically analysed fo in nearly 1000 affectively neutral speech utterances (vowels, words, counting, greetings, read paragraphs and free spontaneous speech) produced by the same 154 men and women, aged 18-67, with two aims: first, to test the methodological validity of comparing fo measures from diverse speech stimuli, and second, to test the prediction that the vast inter-individual differences in habitual fo found between same-sex adults are preserved across speech types. Indeed, despite differences in linguistic content, duration, scripted or spontan--eous production and within-individual variability, we show that 42-81% of inter-individual differences in fo can be explained between any two speech types. Beyond methodological implications, together with recent evidence that inter-individual differences in fo are remarkably stable across the lifespan and generalize to emotional speech and nonverbal vocalizations, our results further substantiate voice pitch as a robust and reliable biomarker in human communication.

When and how does the number of children affect marital satisfaction? An international survey.

The present global study attempts to verify the links between marital satisfaction and the number of children as well as its moderators in an international sample. Data for the study was obtained from our published dataset and included 7178 married individuals from 33 countries and territories. We found that the number of children was a significant negative predictor of marital satisfaction; also sex, education, and religiosity were interacting with the number of children and marital satisfaction, while there were no interactions with economic status and individual level of individualistic values. The main contribution of the present research is extending our knowledge on the relationship between marital satisfaction and the number of children in several, non-Western countries and territories.

Pharyngeal Detection of Staphylococcus aureus as a Possible Factor Related to Disgust Sensitivity in Humans.

Disgust triggers behavioral avoidance of pathogen-carrying and fitness-reducing agents. However, because of the cost involved, disgust sensitivity should be flexible, varying as a function of an individual's immunity. Asymptomatic colonization with Staphylococcus aureus often results from weakened immunity and is a potential source of subsequent infections. In this study, we tested if pharyngeal colonization with S. aureus, evaluated based on a single swab collection, is related to an individual's disgust sensitivity, measured with the Three Domain Disgust Scale. Levels of immunomodulating hormones (cortisol and testosterone), general health, and body adiposity were controlled. Women (N = 95), compared to men (N = 137), displayed higher sexual disgust sensitivity, but the difference between individuals with S. aureus and without S. aureus was significant only in men, providing support for prophylactic hypothesis, explaining inter-individual differences in disgust sensitivity. Men (but not women) burdened with asymptomatic S. aureus presence in pharynx exhibit higher pathogen disgust (p = 0.04) compared to individuals in which S. aureus was not detected. The positive relationship between the presence of the pathogen and sexual disgust was close to the statistical significance level (p = 0.06), and S. aureus colonization was not related with moral disgust domain.

Difference in Perception of Onset of Old Age in Traditional (Hadza) and Modern (Polish) Societies.

Despite relatively clear physiological indicators of old age, little is known about cross-cultural differences in psychological perceptions of the transition to old age. Although recent studies suggest consistency between modern countries, the subjective perception of old age onset in traditional societies remains poorly explored. Therefore, we compared the perception of timing of old age between a traditional tribe of hunter-gatherers (the Hadza) and a Polish sample representing a modern, industrialized population. The results indicate that the Hadza perceive old age onset as being significantly earlier than do the Poles. Furthermore, we found between-gender differences in the Polish sample: men set a lower threshold of old age onset than women. The Hadza showed no between-gender difference. Although the samples were matched for age, a larger proportion of Hadza considered themselves old. We discuss these findings from cultural and demographical perspectives.

Does thinking about coronavirus impact insight and analytical reasoning?

Stress and threats have been shown to influence our cognition and performance. In a preregistered online experiment (N = 446), we examined whether thinking about the ongoing covid-19 pandemic influences creative (insight problem solving) and analytic thinking. We found no support for our a-priori hypothesized effect (decrease in insight problem solving and no change in analytical thinking), however, several unpredicted results emerged. Exploratory analyses revealed that both types of thinking were harmed, yet only in men. Interestingly, the effect of exposure on thinking about covid-19 was indirect and led to careless task completion - again, only in men. We discuss these intriguing results and propose potential explanations along with future studies directions.