The Science Behind a Sexy Voice
Sexual attraction can begin at the outset of hearing another’s voice.
The extra-linguistic cues, hidden within our voice, are programmed to influence certain bodily responses of another and have been crystallized as such by a number of phylogenetic traits passed down from reptiles to mammals to primates to us.
How female fallow deer choose their mates
Male vocalisations are often subject to sexual selection and can be used to assess the quality and condition of the caller in various vertebrates… In most vertebrates, high quality males have larger body sizes that determine higher social status and in turn higher reproductive success… Previous research has emphasised the importance of vocal tract resonances or formant frequencies of calls as cues to body size in mammals. (Vannoni, E., McElligott, G, A., 2008)
The research article above studied the effects of pitch, resonance, formant frequencies (harmonics), and fundamental frequency (the lowest pitch of the voice), on the mating success of male fallow deer. Their findings:
Our study is the first to show that sexually selected vocalisations can signal social dominance in mammals other than primates, and reveals that independent acoustic components encode accurate information on different phenotypic aspects of male quality. (Vannoni, E., McElligott, G, A., 2008)
Female fallow deer rely on acoustic cues related to dominance to evaluate potential mating partners, as higher-ranking males likely have better survival prospects and reproductive success.
These acoustic cues, the significant factors underlying the establishment of a deer’s hierarchy, are the intricacies of a deer’s groan, in so much as “groans of high-ranking males were characterized by lower minimum fundamental frequencies” (Vannoni, E., McElligott, G, A., 2008). In competing for a mate, the voice is used to attract a partner by a number of different variables such as how deep the voice is and the formants (harmonics) that run underneath it, which give the female a clue to how big and long the deer’s neck measures. The deer’s mating groans were also observed to intimidate rival males and prevent clashes. So, when female deers are evaluating the quality of a potential mate, the voice is a deciding factor.
In essence, for fallow deers, the lower the voice the higher the significance for social dominance, and the more likely sex occurs. This might be true for deer, but is it true for humans?
Do humans judge sexual quality in similar ways?
Humans, and the way we perceive our environment (neuroception), are still extremely primitive. Many of the ways we unconsciously react to external stimuli are shared not just with mammals but with reptiles. Fight and flight, an autonomic response we share with deer, is an example, and the fact our body switches between these autonomic states many times a day closes the phylogenetic distance between us and them. Our ability to survive trauma is a neural vestige handed down to us by some of the earliest scaled creatures to walk on this earth; therefore, we must take care not to remove ourselves too far from the Natural order. Our urge to reproduce will look at many facets of a potential mate, and the voice is not outside of our scrutiny:
In humans, men with high androgen (testosterone) levels have voices with low F0 (pitch) and women preferred these males, especially close to ovulation. (Puts, D, A., et al cited in Vannoni, E., McElligott, G, A., 2008)
I’m hesitant to claim that this study proves without a doubt that pitch is a deciding factor for sexual attraction due to its low sample size but vocal pitch has been fiercely studied to reveal that it does affect other areas of our social hierarchy due to its influence on perception.
Indeed, the male voice is lower than females, due to longer vocal folds whereby their growth is exacerbated by testosterone, and Darwin noted that the main driver behind sex differences is sexual selection. Collins (cited in Puts, D, A., et al, 2006) suggested that sex differences in the human voice evolved through sexual selection via female mate choice, and part of that choice can be explained by some of these vocal cues we inherited from our mammalian and primate cousins. As the study suggested above, the lower the pitch, the higher the attraction but I will argue that is only but a small proportion of the other elements in the voice of which I will reveal.
When it comes to social competition, “men who believe they are physically dominant to their competitor lower their voice pitch when addressing him, whereas men who believe they are less dominant raise it” (Puts, D, A., 2006). It seems that low frequency in the voice is a trait we share with deer not only in mating rituals but also in stifling off rivalries. But is it just a deep voice or are there other things going on inside the voice? Before we look at that, how does this competitive edge work outside sexual selection if we are signalling dominance and authority in the voice on an ad-hoc basis?
Dominance, Authority, and Authenticity: What does that sound like?!
A Financial Times piece wrote on the importance of authority in the voice:
“Women can change the way they sound for more impact, but authenticity is crucial” (Financial Times, Rivkah Brown, May 27, 2019).
But what is this “authenticity” in the voice to achieve authority? Does it help your chances of having more sex, with more people? Or like the FT article above, does it provide you with greater chances of becoming a leader, such as a CEO, or both?
Authenticity, referred to in the FT piece, as the “Natural” voice, is commonly thrown around in voice pedagogy and ideology. But no-one truly knows what it is…Authority, or dominance, however, does seem to characterized by a deeper voice as “results show that both men and women select male and female leaders with lower voices” (Klofstad, C, A. et al, 2012).
If social dominance is characterised by a deeper voice, where does that place women, who have biologically shorter vocal folds?
This is where it gets tricky and supports the rising trend in clients asking to make their voice deeper. If social dominance is characterized by a low fundamental frequency in the voice, where does that place women in a social hierarchy given that a female’s vocal folds are biologically smaller, and may never reach the depth of a male’s? Before I go on, I will point out that this tends to invert as an older female’s voice frequency will drop over time whereas a male’s increases.
Some researches have gone so far to say 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. In fact, “we as listeners often associate low voice pitch with positive psychological traits such as competence and intelligence respective to each sex” (Klofstad, C, A. et al, 2012).
But should females drop their pitch to match a lower fundamental frequency which is shown to be an auditory cue signalling social dominance which is twice as hard for females to reach? I don’t profess to have an answer to this but it should be noted that we modulate our voice “in ways that are likely to elicit favourable social appraisals” and shouldn't feel ashamed of doing so (Sorokowski, P., 2019). Most of the time, this modulation, occurs unconsciously, and we have many voices for many social contexts. Your voice will rise when excited and fall when sad. So, modulating your voice, on purpose, to adjust to your context is neither here nor there, and if it triggers biological conditions in the listener's inner ear, then, by all means, use what knowledge we have to your advantage.
So, if females want to have this same impact that low frequency gives upon an audience, where can they go if they can’t get to that lower pitch?
How the voice can convey dominance and sexual quality other than through pitch
It begins by starting to treat your voice like an instrument, rather than an entity that does things of its own accord. We are modulating our voices all the time albeit unconsciously, so what is the difference doing it with purpose? In fact, purposefulness requires mindfulness, and honing skills with your voice can become a meditative practice.
Commanding an audience, implying authority, is not just pitch — and sexual selection in the voice, I claim, is not merely that either.
A voice can find depth, without having to alter the pitch, by increasing tone, amplitude and resonance. Each of these elements increase the voices modulation and frequency range. Remember, the voice is made of a myriad of overtones and harmonics that sit either above or below your primary frequency and it is these elements that give “depth” to the voice. To learn how the voice can increase range and depth read here.
What you can take out of all this
A lower-pitched voice signals a larger body mass that incites certain female species to find attractive. It is also shown to have a high correlation to people holding leadership positions. I will not claim that pitch is the deciding factor for sexual attraction between humans, and of course, we know it isn’t, but we must also not throw the baby out with the bathwater, as it is a biological trait shared between many animal species, of which we share many phylogenetic relationships.
A deeper voice isn’t just made with pitch; there are harmonics and overtones that exist above and below your primary frequency that help embellish and modulate the sound of your voice and can be discovered to add capacity to the width and range of your speaking voice. By honing in on tone and resonance you may begin to understand why leaders share a common possession of a deeper voice; it takes a small measure of bravery to stand behind your words in the face of sharp criticism and you can’t have tone without courage.
Vannoni, A., McElligott, A, G. (2008). Low-Frequency Groans Indicate Larger and More Dominant Fallow Deer (Dama dama) Males. PLoS One. 3, 1–8.
Klofstad, C, A., Anderson, R, C., Peters, S. (2012). Sounds like a winner: voice pitch influences perception of leadership capacity in both men and women. The Royal Society. 279, 2698–2704.
Puts, D, A., Gaulin, S, J, C., Verdolini, K. (2006). Dominance and the evolution of sexual dimorphism in human voice pitch. Evolution and Human Behaviour. 27, 283–296.
Sorokowski, P., Puts, D, A., Johnson, J, Żółkiewicz, O., Oleszkiewicz, A., Sorokowska, A., Kowal, M., Borkowska, B., Pisanski, K. (2019). Voice of Authority: Professionals Lower Their Vocal Frequencies When Giving Expert Advice. Journal of Nonverbal Behavior. 43, 257–269.