All you have to do is watch nearly any depiction of female orgasm on screen to get an idea of how a woman is “supposed” to react during sex.

From “When Harry Met Sally” to “Sex and the City” to your basic porn film, women in the throes of passion aren’t just shouting their ecstasy from the rooftops – they’re moaning with pleasure. Loudly.

But is this just cinematic license, or is there really something to noisy sex?

Experts wondered the same thing. Last year, Gayle Brewer of the University of Central Lancashire and Colin Hendrie of the University of Leeds published their research on the topic – technically known as “copulatory vocalization” – in the Archives of Sexual Behavior. In the study, they asked 71 sexually active heterosexual women between ages 18 and 48 for more details about vocalization during sex.

The researchers found that many of the women did make noise, but not necessarily while they were having an orgasm. Instead, 66% said that they moaned to speed up their partner’s climax, and 87% stated that they vocalized during sex to boost his self-esteem.

Are female orgasms really just a ‘bonus’?

“While female orgasms were most commonly experienced during foreplay, copulatory vocalizations were reported to be made most often before and simultaneously with male ejaculation,” write the researchers. Women also reported making noise to relieve boredom, fatigue and pain/discomfort during sex.

So is female vocalization during sex just a performance for a guy’s benefit? (After all, Meg Ryan’s over-the-top moans were meant to prove a point to “Harry” that men are easily duped by a fake orgasm.)

“There isn’t a lot of research in this area,” says Kristen Mark, a sexuality researcher at Indiana University, “but we’re bombarded with images through mainstream media that tell us moaning is associated with orgasm and sexual pleasure. So it would be a fairly wise faking strategy to moan since men already tend to associate moaning with orgasm.”

Of course, there’s nothing smart about faking it.

“If you’re faking an orgasm, you are signaling to your partner that he is doing everything right, when in fact he isn’t,” says sex educator and author Patty Brisben. “Use moaning as a way of signaling that you are excited and things really are feeling good, not as a way to hide that they aren’t.”