Pregnancy causes a ton of changes in a person's body — some of them more obvious than others — but what's really fun to track are the changes that get talked about less often. For example, a new study found that a woman's voice may deepen after giving birth and it's really fascinating to think about. Of all the biological changes that get touched on during and after pregnancy, a woman's voice rarely gets a mention.
Of course, women's voices changing over time isn't brand new information. For example, scientists have previously found that a woman's voice pitch may increase around ovulation each month, as The Guardian previously reported. Lead researcher of that study, Greg Bryant, told The Guardian in 2008 this might be due to women trying to "enhance their femininity." He told the publication, "The closer the women get to ovulation, the greater the increase in their pitch."
As for this most recent study, researchers at the University of Sussex's Voice Lab took inspiration from previous studies to see if pregnancy can also affect a woman's voice pitch. Their study, recently published in the Evolution and Human Behavior journal, concluded that the pitch of new mothers' voices may drop after giving birth to their first child.
It might seem a little out there, but sit with it. Women have noted lower voices after pregnancy well before this study. Back in 2015, Adele publicly discussed how a combination of pregnancy and surgery changed her voice. "Also in pregnancy my voice got a lot lower, which is why 'Skyfall' is so low. I couldn't get up there for (the high notes in) 'Skyfall,'" she told talk show host Graham Norton in 2015, according to Xpose.
In order to better understand what Adele meant, Made for Mums came up with a short listening test. Take a quick listen to Adele's "Skyfall." This track was released in 2012, according to Billboard, which was the same year Adele was pregnant with and gave birth to her son, Angelo. After, take a listen to "When We Were Young," released in 2016. "Her voice should sound back to normal," Made for Mums noted of the 2016 single.
Adele herself recognized that "Skyfall" was not within her normal singing range. During a March 2017 concert, as the Daily Mail reported, the singer asked her audience to bear with her when attempting to hit the low notes in "Skyfall." According to the Daily Mail, Adele said:
When I wrote that song, I was heavily pregnant. And a side effect or symptom, however you felt about your pregnancy, was my voice got a bit lower. So, my larynx dropped.
Although the new study conducted by the University of Sussex's Voice Lab specified women's voices changing for roughly a year, Katarzyna Pisanski, the lead researcher for the study, wrote for The Conversation that "Adele says her voice is only now returning to its pre-pregnancy level".
For this recent study, Pisanski and the other researchers reviewed nearly a decade's worth of voice recordings — over 600 in total, from 20 mothers and 20 control women who had never given birth — and found that the new mothers' "mean voice pitch dropped by more than 5%," as The Guardian explained.
Although the study reached its conclusion on whether or not a woman's voice pitch can deepen, that doesn't mean scientists know exactly why this can happen. There are some reasons tossed around, namely the effect of hormones, as Pisanski explained in their findings. However, the drop in pitch could also be related to the exhaustion that comes with raising a newborn baby. But another interesting possibility, according to a press release of the study, is something called behavioral voice modulation. Pisanski explained to The Guardian:
Research has already shown that people with low-pitched voices are typically judged to be more competent, mature, and dominant, so it could be that women are modulating their own voices to sound more authoritative, faced with the new challenges of parenting.
And she's right; for example, as WIRED reported in 2012, a different study found that people tend to vote for politicians with "a lower-pitched voice" because they view them as more "socially dominant." As the Daily Mail reported of these most recent findings, new mothers may be trying to sound "more authoritative." Still, there's plenty more research to be done on the subject, but for now, it's interesting enough to know that this phenomenon exists.