If you want to know whether a man is attracted to you, just listen to the tone of his voice, according to a new U.K. study.

Heterosexual men and women modulate their speaking voices when they’re attracted to a member of the opposite sex, researchers at the University of Liverpool, in England, and the University of Stirling, in Scotland, have found.

Researchers studied the audio recordings of over 200 human voices and determined that men in particular tend to lower their voices when speaking to women they deem attractive.

Scott Bea, a clinical psychologist at Cleveland Clinic who was not involved in the research, said that quelling nerves and not being self-conscious can increase the likelihood of a successful courtship.

“In instances where people are too struck with what’s going on inside them, rather than outside them, their voice may modulate up as part of an anxiety response, in which case they may become a less-attractive partner actually,” he said.

The study was published in the journal Evolution and Human Behavior.