Scientists have known for decades that women’s voice pitch lowers after menopause. Other research has suggested that voice pitch increases around ovulation each month in women of reproductive age and that men prefer voices of women recorded during this fertile period.
Now, a more recent study, published in Evolution & Human Behaviour, reveals the pitch of a new mom’s voice drops after giving birth. However, the researchers found this lasts only a year after birth, after which the pitch of your voice goes back up to what it was before you fell pregnant.
According to Katarzyna Pisanski, Research Fellow in Bioacoustics and Voce Studies at the University of Sussex in Britain, this is the first scientific evidence that pregnancy affects women’s voices. This is even though many women claim to have personally experienced it. The singer Adele, for example, after giving birth to her son, reported that her voice pitch dropped dramatically.
Pregnancy involves a significant change in hormones
The study, published in Evolution & Human Behaviour, turned to online archives of interviews with women who were recorded before, during, and after their first pregnancy, many who were singers and actresses.
While the researchers couldn’t explain the mechanisms driving the voice changes, they say the likely culprit is the fluctuations in your hormone levels, particularly testosterone, oestrogen and progesterone. These hormones rise during your pregnancy and drops off sharply after childbirth.
With regards to the pitch of your voice, the researchers pointed out that sex hormones have a direct effect by increasing the effective mass of the vocal folds and slowing their vibratory pattern, thus lowering the pitch. “They might also have indirect effects on voice production by affecting motor and sensory processes in the brain that are involved in the control of the larynx – your voice box.”
Of course, every new mom knows that raising a baby can be physically and mentally exhausting, so the drop in voice pitch after childbirth could also be related to fatigue or motivational changes.
Either way, we’re betting your other half will enjoy your new husky tone… while it lasts!
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