Every night in my building I’m treated to a concert of loud sex. Like clockwork, at 6:30, the soundtrack begins and “Ooh ooh ooh ooh!” rings out with the same rhythmic regularity and decibel level.

Frequently – “Oh God!” – the Lord is called upon to listen too. And between the young heterosexual couple down the hall and the man who regularly visits my door to slip a miniature Bible under the crack, I sometimes feel like I’m living in a Baptist meetinghouse.

But why is it always the woman making all the noise? And is it an expression of pleasure, or something else? As it turns out, recent science offers some tantalizing hints.

Researchers Gayle Brewer of the University of Central Lancashire and Colin A. Hendrie of the University of Leeds wondered too. In a 2011 study on copulatory vocalization (i.e., sex noises), published in the Archives of Sexual Behavior, they asked a group of 71 sexually active, heterosexual women, ages 18 to 48, to answer a questionnaire about their vocalizations during sex and whether or not they correlated with orgasm. The answer most often was yes – but not with their own.

Although female orgasms were reportedly most commonly experienced during foreplay, their vocalizations were reported to occur most frequently before and simultaneous with male ejaculation.

So basically the women’s sex noises most frequently accompanied their partner’s orgasm. Why? It turns out, it’s because they wanted to help their partners out.

Sixty-six percent reported making noise to accelerate their partner’s ejaculation. Ninety-two percent believed these vocalizations upped their partner’s self-esteem (87 percent reported vocalizing for this purpose). Other reported reasons included speeding things up, “to relieve discomfort/pain, boredom, and fatigue in equal proportion, as well as because of time limitations.”

Sex has always had an aspect of performance to it. Even in the animal kingdom, noises are made and poses struck: In fact, female Barbary macaque monkeys let out a yell to help their male partners climax too.

Research reveals that for some polygamous baboons, female copulatory vocalization depends on how close the female is to ovulation, indicating her availability and fertility to other males who may want to mate. Alternatively, the male turtle utters a strangely human sigh while penetrating the silent, slightly bored-looking female.

And then there’s porn. Today, the Internet’s endless archive of videos, and their constant availability, must affect how we think about – and therefore have – sex. It’s been argued that certain mainstream heterosexual porn memes – such as gasping and moaning or talking dirty, not to mention widespread trends in pubic grooming – are replicated by heterosexual women especially, with the idea that their men will either be turned on or just expect as much.

Perhaps of greater impact, the images of sex that Hollywood perpetuates are subject to regulations that challenge filmmakers to show without actually showing – an opportunity for non-visuals like vocalization to pick up the slack. Of course, Meg Ryan’s iconic Katz’s Deli orgasm in “When Harry Met Sally” (“I’ll have what she’s having”) showed us that vocal pleasure can be faked – and released under an R rating.

Even in your average PG-13 Hollywood sex scene, sound often works overtime to make up for what’s lacking in pubic hair, nipples and the sometimes-awkward repositioning of reality. The MPAA’s rules about what you can show are murky, demonstrated recently when “Blue Valentine” was slapped with an NC-17 designation, ostensibly because of its female oral sex scene (the designation was later reversed on appeal).

In a globalized world of media sharing, are sex noises culturally specific or do they still vary around the world? “Porn is one valid piece of the puzzle,” said Debby Herbenick, sexual health educator at The Kinsey Institute and author of “Great in Bed.”

“But there are nuanced issues as well,” for instance, where you’re living in a given culture, whether in an apartment building, a suburban house, or in your parents’ attic. “There are different places on the spectrum of if you’re likely to be heard, where you live, if you want to be heard, or don’t care, etc., which is probably the same from culture to culture.”

Gayle Brewer, of the aforementioned 2011 study, hypothesizes that in relation to the U.K., “Vocalizations may serve a similar function in other cultures although the degree to which women display these vocalizations (commonly interpreted as a sign of sexual pleasure) may be influenced by the societal restrictions placed on women’s active engagement in sexual behavior.”

And then, some of it is probably biological. The connection between physical activities and vocalization – from athletics to enjoying food to sex – is an interesting one. “The question is how much is show versus a release of physical bodily experience,” said Herbenick. “There’s a lot of unexplored territory. In the relatively young, small field of sex research, [sex vocalization] is just one of those accidentally neglected things.”

Unfortunately, not nearly enough research has been done on the subject of sex vocalization. (A documented, though unvalidated, account of the diversity of orgasm vocalizations of 10 women conducted by a 13th century Arabic physician, Al-Sayed Haroun Ibn Hussein Al-Makhzoumi, seems to exist.) But if you’re reading, woman down the hall, I congratulate you on having a very regular and vocal sex life, and hope that your partner really does know what he’s doing. Because what could be sexier for him than if he were truly and confidently giving you something to scream about?