In medical school, my roommate Enzyme and I had a dorm apartment next to a German couple, who were both grad students. We shared one big wall with them.
This pair were into REALLY loud sex. Moaning. Screaming. And she would scream "Fuck me, Heinrich!" repeatedly, with a bizarrely musical intonation. Like an opera number.
I have nothing against sex. Or others having sex. And noise like this in a cheap apartment is part of the college experience.
But this pair could really go at it. And it drove us nuts.
It's easy to tell someone else to turn down the TV or music. It's a lot harder to say "Hey! Can you stop humping so loud?!!!"
I think the idea was Enzyme's, but after 20 years I'm not sure. I found a used classical music CD at the college bookstore, and brought it home. We were listening to it while studying when the idea began.
We set up some speakers facing the mutual wall, and waited for the Brünhilda and Heinrich show to begin one night. It didn't take long.
And then, LOUDLY, we put on Wagner's piece "Flight of the Valkyries". Although it was tricky, we were able to time the main "dah-dah-dah-DUM-dum" part to coincide with her repeatedly screaming "Fuck me, Heinrich!" It actually sounded pretty good, like some sort of operatic porn.
After the curtain went down, we turned off the music.
A few minutes later there was some loud discussion in German (likely them swearing at us).
We never heard them going at it again. I suspect they started using another room. At least then it was the other neighbor's problem.