But contrary to expectations, they also found that these men aren’t better off in the semen department. In fact, by one measure of sperm quality — sperm concentration in ejaculate — men with the attractive voices appeared to have a disadvantage.

This is a surprise because females, both humans and of other species, are believed to glean information about male virility through secondary sexual traits, such as facial hair and muscle mass in humans and other traits in other animals, such as colorful plumage in birds.