Expression of gender in the human voice: investigating the “gender code”

We can easily and reliably identify the gender of an unfamiliar interlocutor over the telephone. This is because our voice is “sexually dimorphic”: men typically speak with a lower fundamental frequency (F0 - lower pitch) and lower vocal tract resonances (ΔF – “deeper” timbre) than women. While the biological bases of these differences are well understood, and mostly down to size differences between men and women, very little is known about the extent to which we can play with these differences to accentuate or de-emphasise our perceived gender, masculinity and femininity in a range of social roles and contexts. The general aim of this thesis is to investigate the behavioural basis of gender expression in the human voice in both children and adults. More specifically, I hypothesise that, on top of the biologically determined sexual dimorphism, humans use a “gender code” consisting of vocal gestures (global F0 and ΔF adjustments) aimed at altering the gender attributes conveyed by their voice. In order to test this hypothesis, I first explore how acoustic variation of sexually dimorphic acoustic cues (F0 and ΔF) relates to physiological differences in pre-pubertal speakers (vocal tract length) and adult speakers (body height and salivary testosterone levels), and show that voice gender variation cannot be solely explained by static, biologically determined differences in vocal apparatus and body size of speakers. Subsequently, I show that both children and adult speakers can spontaneously modify their voice gender by lowering (raising) F0 and ΔF to masculinise (feminise) their voice, a key ability for the hypothesised control of voice gender. Finally, I investigate the interplay between voice gender expression and social context in relation to cultural stereotypes. I report that listeners spontaneously integrate stereotypical information in the auditory and visual domain to make stereotypical judgments about children’s gender and that adult actors manipulate their gender expression in line with stereotypical gendered notions of homosexuality. Overall, this corpus of data supports the existence of a “gender code” in human nonverbal vocal communication. This “gender code” provides not only a methodological framework with which to empirically investigate variation in voice gender and its role in expressing gender identity, but also a unifying theoretical structure to understand the origins of such variation from both evolutionary and social perspectives

Control of voice gender in pre-pubertal children

Adult listeners are capable of identifying the gender of speakers as young as 4 years old from their voice. In the absence of a clear anatomical dimorphism in the dimensions of pre-pubertal boys' and girls' vocal apparatus, the observed gender differences may reflect children's regulation of their vocal behaviour. A detailed acoustic analysis was conducted of the utterances of 34 6- to 9-year-old children, in their normal voices and also when asked explicitly to speak like a boy or a girl. Results showed statistically significant shifts in fundamental and formant frequency values towards those expected from the sex dimorphism in adult voices. Directions for future research on the role of vocal behaviours in pre-pubertal children's expression of gender are considered

Why stopping acid attacks is a matter of chemical weapons control

The use of acid as part of violent crime is apparently on the rise in the UK, and various efforts are being made to reverse what’s become a very disturbing trend

What makes a voice masculine: physiological and acoustical correlates of women's ratings of men's vocal masculinity

Men's voices contain acoustic cues to body size and hormonal status, which have been found to affect women's ratings of speaker size, masculinity and attractiveness. However, the extent to which these voice parameters mediate the relationship between speakers' fitness-related features and listener's judgments of their masculinity has not yet been investigated. We audio-recorded 37 adult heterosexual males performing a range of speech tasks and asked 20 adult heterosexual female listeners to rate speakers' masculinity on the basis of their voices only. We then used a two-level (speaker within listener) path analysis to examine the relationships between the physiological (testosterone, height), acoustic (fundamental frequency or F0, and resonances or ΔF) and perceptual dimensions (listeners' ratings) of speakers' masculinity. Overall, results revealed that male speakers who were taller and had higher salivary testosterone levels also had lower F0 and ΔF, and were in turn rated as more masculine. The relationship between testosterone and perceived masculinity was essentially mediated by F0, while that of height and perceived masculinity was partially mediated by both F0 and ΔF. These observations confirm that women listeners attend to sexually dimorphic voice cues to assess the masculinity of unseen male speakers. In turn, variation in these voice features correlate with speakers' variation in stature and hormonal status, highlighting the interdependence of these physiological, acoustic and perceptual dimensions

Children can control the expression of masculinity and femininity through the voice

Pre-pubertal boys and girls speak with acoustically different voices despite the absence of a clear anatomical dimorphism in the vocal apparatus, suggesting that a strong component of the expression of gender through the voice is behavioural. Initial evidence for this hypothesis was found in a previous study showing that they can alter their voice to sound like a boy or like a girl. However, whether children can spontaneously modulate these voice components within their own gender in order to vary the expression of their masculinity and femininity remained to be investigated. Here, seventy-two English-speaking children aged 6 to 10 were asked to give voice to child characters varying in masculine and feminine stereotypicality to investigate whether primary school children spontaneously adjust their voices sex-related cues in the voice – fundamental frequency (F0) and formant spacing (ΔF) – along gender stereotypical lines. Boys and girls masculinised their voice, by lowering F0 and ΔF, when impersonating stereotypically masculine child characters of the same sex. Girls and older boys also feminised their voice, by raising their F0 and ΔF, when impersonating stereotypically feminine same-sex child characters. These findings reveal that children have some knowledge of the sexually dimorphic acoustic cues underlying the expression of gender, and are capable of controlling them to modulate gender-related attributes, paving the way for the use of the voice as an implicit, objective measure of the development of gender stereotypes and behaviour

Improving access to sexual violence support for marginalised individuals: findings from the LGBT and BME communities

Statistics suggest that survivors of sexual violence from BME and LGBT communities are less likely to access specialist support than other members of the general population. This paper highlights specific barriers these communities face in accessing support services and how they could be addressed by these services, using data from a case study conducted in the city of Brighton and Hove, UK. It also takes the original step of comparing questionnaire and interview data from survivors with questionnaire and interview data from practitioners working with the BME and LGBT communities. Recommendations are identified for sexual violence services and social workers working with these survivors that are missing from existing literature. These include a critique of the empowerment discourse commonly employed by support services, use of intersectional feminist theory to inform practice, and recommendations for 'community-embedded' support services

“This is what a mechanic sounds like.” Children’s vocal control reveals implicit occupational stereotypes

In this study, we explored the use of variation in sex-related cues of the voice to investigate implicit occupational stereotyping in children. Eighty-two children between the ages of 5 and 10 years took part in an imitation task in which they were provided with descriptions of nine occupations (three traditionally male, three traditionally female, and three gender-neutral professions) and asked to give voices to them (e.g., “How would a mechanic say . . . ?”). Overall, children adapted their voices to conform to gender-stereotyped expectations by masculinizing (lowering voice pitch and resonance) and feminizing (raising voice pitch and resonance) their voices for the traditionally male and female occupations, respectively. The magnitude of these shifts increased with age, particularly in boys, and was not mediated by children’s explicit stereotyping of the same occupations. We conclude by proposing a simple tool based on voice pitch for assessing levels of implicit occupational-gender stereotyping in children

Effect of formant frequency spacing on perceived gender in pre-pubertal children's voices

<div><p>Background</p><p>It is usually possible to identify the sex of a pre-pubertal child from their voice, despite the absence of sex differences in fundamental frequency at these ages. While it has been suggested that the overall spacing between formants (formant frequency spacing - ΔF) is a key component of the expression and perception of sex in children's voices, the effect of its continuous variation on sex and gender attribution has not yet been investigated.</p><p>Methodology/Principal findings</p><p>In the present study we manipulated voice ΔF of eight year olds (two boys and two girls) along continua covering the observed variation of this parameter in pre-pubertal voices, and assessed the effect of this variation on adult ratings of speakers' sex and gender in two separate experiments. In the first experiment (sex identification) adults were asked to categorise the voice as either male or female. The resulting identification function exhibited a gradual slope from male to female voice categories. In the second experiment (gender rating), adults rated the voices on a continuum from “masculine boy” to “feminine girl”, gradually decreasing their masculinity ratings as ΔF increased.</p><p>Conclusions/Significance</p><p>These results indicate that the role of ΔF in voice gender perception, which has been reported in adult voices, extends to pre-pubertal children's voices: variation in ΔF not only affects the perceived sex, but also the perceived masculinity or femininity of the speaker. We discuss the implications of these observations for the expression and perception of gender in children's voices given the absence of anatomical dimorphism in overall vocal tract length before puberty.</p></div

Physiological and perceptual correlates of masculinity in children’s voices

Low frequency components (i.e. a low pitch (F0) and low formant spacing (ΔF)) signal high salivary testosterone and height in adult male voices and are associated with high masculinity attributions by unfamiliar listeners (in both men and women). However, the relation between the physiological, acoustic and perceptual dimensions of speakers’ masculinity prior to puberty remains unknown. In this study, 110 pre-pubertal children (58 girls), aged 3 to 10, were recorded as they described a cartoon picture. 315 adults (182 women) rated children’s perceived masculinity from the voice only after listening to the speakers’ audio recordings. On the basis of their voices alone, boys who had higher salivary testosterone levels were rated as more masculine and the relation between testosterone and perceived masculinity was partially mediated by F0. The voices of taller boys were also rated as more masculine, but the relation between height and perceived masculinity was not mediated by the considered acoustic parameters, indicating that acoustic cues other than F0 and ΔF may signal stature. Both boys and girls who had lower F0, were also rated as more masculine, while ΔF did not affect ratings. These findings highlight the interdependence of physiological, acoustic and perceptual dimensions, and suggest that inter-individual variation in male voices, particularly F0, may advertise hormonal masculinity from a very early age

Spontaneous Voice Gender Imitation Abilities in Adult Speakers

Background The frequency components of the human voice play a major role in signalling the gender of the speaker. A voice imitation study was conducted to investigate individuals' ability to make behavioural adjustments to fundamental frequency (F0), and formants (Fi) in order to manipulate their expression of voice gender. Methodology/Principal Findings Thirty-two native British-English adult speakers were asked to read out loud different types of text (words, sentence, passage) using their normal voice and then while sounding as ‘masculine’ and ‘feminine’ as possible. Overall, the results show that both men and women raised their F0 and Fi when feminising their voice, and lowered their F0 and Fi when masculinising their voice. Conclusions/Significance These observations suggest that adult speakers are capable of spontaneous glottal and vocal tract length adjustments to express masculinity and femininity in their voice. These results point to a “gender code”, where speakers make a conventionalized use of the existing sex dimorphism to vary the expression of their gender and gender-related attributes