If you've ever felt an attraction to someone whom you've only heard and never actually seen, it may be because our senses are trained to pick up a potential mate's genetic health and reproductive fitness, which is reflected in the symmetry of one's body via the sound of his or her voice.
In a study published in the Journal of Nonverbal Behavior, participants listened to previously recorded voices and rated their levels of attractiveness according to nine traits, including approachability, intelligence, sexiness and warmth.
The group concluded that men whose voices ranked as most approachable, intelligent, sexy and warm — and women whose voices were deemed most approachable, sexy and as most likely to get dates — were the most attractive overall.
The voices rated as most attractive were from those whose bodies were the most symmetrical. But a sexy voice and sexy body has nothing to do with the attractiveness of one's face, at least according to one of the lead researchers.
But what are the specific qualities of an attractive voice? When researchers used machines to try and objectively quantify the characteristics of a "sexy voice," the results were inconclusive. Just like our sense of smell, apparently our perception of sound is just another way that our sneaky genes are inherently playing matchmaker for us.