Relationships between vocal characteristics and body size and shape in human males: an evolutionary explanation for a deep male voice.

A deep male voice may play a role in courtship and competitive behaviours in humans by attracting female mates and indicating body size to male competitors. The current correlational study investigated the relationship between vocal measures (fundamental and formant frequencies) and both body size and shape. Vocal samples and physical measures were obtained from 50 heterosexual male volunteers. A significant negative relationship was found between fundamental frequency and measures of body shape and weight. Further, a significant negative relationship was found between formant dispersion (the relationship between successive formant frequencies) and measures of body size as well as body shape. Findings are discussed in relation to the 'good genes' model of sexual selection and the size exaggeration theory of laryngeal descent.