If you're like most women, you haven't considered the pitch of your voice since middle school choir practice...but maybe you should.
In one experiment, Dr. Gordon Gallup, a professor at the State University of New York at Albany, asked 10 men to rate the attractiveness of 10 female voices. Some audio clips came from the same women at different times during their menstrual cycles. During ovulation, women produce more estrogen, which raises the pitch of their voices.
Across the board, the men said they preferred the higher-pitched voices, an unconscious indication of fertility. "When females are midcycle, when they're the most fertile, the most likely to conceive, their voices are rated as being significantly more attractive," he says.