Men can come to know when their partners are having their periods just by listening to their voice, a new study reveals.
The study was conducted by two psychologists, Nathan Pipitone at Adams State College and Gordon Gallup at SUNY Albany, who made three groups of men listen to voice recordings of 10 women.
The women were recorded counting one to five four different times over a period of one full menstrual cycle.
The men were made to listen to all the recordings and were asked to identify which recordings were made during a woman's periods. The researchers found that men managed to identify the correct tape 35 percent of the time.
The study is published in the journal Ethology.