Men can sense womens' menstrual cycles

POPSCI: Men can decode womens' menstrual cycles. The voice is the key.

Hormones induce the vocal changes that give women away. “Vocal production is closely tied to our biology,” [Nathan] Pipitone says of men and women. For example, “Cells from the larynx and vagina are very similar and show similar hormone receptors.” The result is that, “The sound of a person’s voice contains a surprising amount of reproductively relevant information,” [Gordon] Gallup says. The obvious example: By speaking on the phone, we can determine a person’s gender and age. But researchers have also shown that voices alone can be used to directly and indirectly predict characteristics like facial appearance, body type, physical strength and even sexual behavior.