Apparently, 17 percent of music fans who listen through Apple AirPods—those odd little wireless earphones seen dangling out of the ears of the 35 million people who bought them in 2018 alone, according to Apple Insider—enjoy leaving the Bluetooth devices in their ears when they have sex.

At least, that’s if the numbers from a survey conducted by the online ticket broker site TickPick are to be believed. And if the survey is accurate, that would mean nearly 6 million people, just in 2018, leave their AirPods in during their most intimate encounters. Of course, AirPods have been on the market since December of 2016 and are reportedly Apple’s most popular accessory product, so the number of AirPod-leaving-in sexually active people is likely much higher.

While having sex to background music is hardly a novel concept, the phenomenon of only one participant listening to that music in a way that likely drowns out any communication from one’s partner seems like a sexual practice that has gone unreported until now. Unfortunately, as the tech news site CNet pointed out, the TickPick survey contained no follow-up questions, so we are left in the dark as to why anyone—much less six million people—would want to keep their AirPods, or any brand of earbuds, in their ears during sex, forcing all communication between partners to be visual or tactile.

But the TickPick survey also contained some other details about the sexual practices and perferences of devoted music listeners. For example, when the survey broke results down by musical genre, it revealed that heavy metal fans are the most sexually responsible; that is, the most likely to use contraception.

At the same time, metalheads were also the second-most likely to say that they had a sexual fetish of some kind, with 41.2 percent acknowledging their fetishism. Top honors in that category, however, belonged to fans of EDM (electronic dance music), 43.8 percent of whom said they had a sexual fetish.

But fans of “classic rock” were least likely to enjoy a fetish, with only one in three acknowledging that preference.

Country music fans, at 36.9 percent, were most likely to say they enjoyed anal sex, while jazz fans (27.7 percent) were most prone to having a foot fetish.

The survey also contained some relationship advice, showing that sexual partners who say that they share musical tastes with each other appear to be far more satisfied with their sex lives (79.6 percent) than those who said that their musical tastes differed from their partner. Of those with different musical tastes, less than half (43.6 percent) said that they found their sex lives satisfactory.