The Surprising Reason Women's Voices Are Getting Deeper

Woman Speaking

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AnnaMarie Houlis
AnnaMarie Houlis
Women's voices have long been studied — especially with regards to how women's voices affect the perception of them in the workplace. Recently, researchers looked into vocal fry or "creaky voice" (a specific type of phonation caused by slackening the vocal cords) and how it affects women in the workplace. And, this time, scientists have looked into why women's voices seem to have gotten deeper in the last few decades. Women today speak at a deeper pitch than the generations of women before them, which researchers believe is largely because of changing power dynamics between men and women.
Study after study has suggested that low voices and "masculine" voices are an asset to leaders. A wealth of research suggests that we prefer low voices because we perceive people with low voices as physically stronger, more competent and more trustworthy. This holds true for both men and women with low voices, though studies show that men with low voices are considered more attractive while the same can't be said for women.
Perhpas strength, competence and trustworthiness — three major qualities of a leader — are how women are hoping to appear, since their voices have been dropping over the years as evermore women move into leadership roles. 
In scientific terms, the “fundamental frequency” in women's voices has dropped by 23 Hz over five decades — from an average of 229 Hz (about an A# below middle C) to 206 Hz (about a G#). What this means is that researcher Cecilia Pemberton of the University of South Australia heard an audible difference in women's voices when she compared archival recordings of women talking in 1945 with more recent recordings taken in the early 1990s.
Pemberton studied the voices of two groups of Australian women ages 18 to 25 years. Her team controlled for any potential demographic factors by making sure that all of the women were university students and that none of them smoked. They also noted that some women in the 1990s group may have been taking contraceptive pills, which could have lead to hormonal changes that can alter the voice. But when the team removed these women from their sample, the drop in pitch remained constant.
The researchers speculate that, as more women rise through the ranks, they've adopted deeper tones to project authority and dominance in their workplaces.
This is nothing really new for the research world. Joey Cheng of the University of Illinois at Urbana-Champaign performed an experiment with groups of four to seven participants who were tasked with ranking the items that an astronaut would need to survive a disaster on the moon. At the end of the experiment, she asked each participant to privately describe the group and each member's dominance. She found that most participants shifted the pitch of their voice within the first few minutes of that conversation, which later predicted their ranking within the group. Those who had lowered their pitch ended up with a higher social rank and were considered the most dominant within the group, while the opposite was true for those who raised their pitch.
But a low voice doesn't just determine how we perceive someone. Low voices can also lead to closing pay gaps and earning companies money.
For example, women in the Netherlands consistently talk in deeper voices than women in Japan, according to a study titled Sociocultural Aspects of Pitch Differences between Japanese and Dutch Women. And in Japan, there's a much larger gender pay gap than in the Netherlands, according to the 2017 OECD report, The Pursuit of Gender Equality: An Uphill Battle.
Likewise, a study conducted by a student at Duke University found that deeper voices lead to bigger salaries. The study focused on the pitch levels of prominent CEOs and found that a mere one percent decrease in pitch led to a CEO’s company having $30 million more in assets. In fact, CEOs with deeper voices had a salary that was, on average, $19,000 higher than their peers.
The fact that a deeper voice can lead to perceived dominance and, ultimately, success, is largely why former UK prime minister Margaret Thatcher employed a professional speech coach to help her to sound more authoritative, deliberately dropping the pitch of her voice by 60 Hz, according to The Telegraph. The research is consistent and, as evermore women move into leadership roles, the trend suggests that their voices will get deeper.
AnnaMarie Houlis is a multimedia journalist and an adventure aficionado with a keen cultural curiosity and an affinity for solo travel. She's an editor by day and a travel blogger at by night.