People's voices can reveal their sex, their age, how they are feeling and recent studies have even suggested that women's voices might also contain hints that men can read about how close they are to ovulation. A new study, however, published today in the journal PLoS ONE, questions the view that women broadcast reproductive information in their voice.
Previous studies in this area have typically relied on the comparison of voices recorded in just two phases in the cycle: high conception risk vs. low conception risk. This new work, on the other hand, looked at variation in the voice throughout the entire menstrual cycle - a crucial step to evaluate the potential information contained in any observed voice changes.
Their results showed that the overall variation in women's vocal quality throughout the whole cycle precludes unequivocal identification of the period with the highest conception risk. Specifically, while they found that the women studied spoke with the highest tone (suggested by previous studies to be associated with attractiveness) just prior to ovulation, the tone rose again to levels indistinguishable from pre-ovulation shortly after ovulation, making it a very poor mating clue. Furthermore, they found that the men studied showed only a very slight preference for pre-ovulation voices relative to voices recorded during ovulation.
The authors conclude that women's voices do not provide reliable information about the timing of ovulation, confirming the view that information about reproductive state is 'leaked' rather than broadcast. In an interesting further finding, the study found that women's voice were harsher and more irregular during menstruation, providing scientific data to explain why female opera singers may be granted 'grace days' during menstruation.