Women's voice attractiveness varies across the menstrual cycle

We investigated ratings of female voice attractiveness as a function of menstrual cycle phase. Women had their voices recorded at four different times during their menstrual cycle. Voice samples were categorized from low to high conception risk based on menstrual cycle phase and empirical pregnancy data. Results showed a significant increase in voice attractiveness ratings as the risk of conception increased across the menstrual cycle in naturally cycling women. There was no effect for women using hormonal contraceptives. Previous research shows that the sound of a person's voice appears to serve as an honest signal of fitness, and our results show perceptual shifts in women's voices that match the predicted output of an independent and well-designed fertility monitoring system. More work is needed to identify the biological mechanisms that underlie these perceptual differences, but growing evidence points to the impact of hormones on the larynx as being the source of these changes. (C) 2008 Elsevier Inc. All rights reserved.