Sometimes I think my upstairs neighbors like being loud just for the sake of being loud. It's not my thing. First of all, I live alone, so I don't have anyone to yell at/to. Second, I can take three steps without falling over or crashing into something. Okay, I don't know if that's exactly what they're doing up there, but it sure sounds like it. Third, when it's sexy time: a) it's just me so; b) it's not as bed-shakingly, floor squeakingly obnoxious.
I just don't get it. These aren't huge apartments. You can't tell me that it's impossible for the person/people you're living with to hear you in another room if you use a normal speaking voice. And if the other person is hard of hearing, then you can't tell me it's too hard to get up and go to that person to speak to them. Oh wait, I guess it is, since it seems you have a serious equilibrium problem.
And I'm not opposed to people having sex. But there are quiet hours here and they start around 10-10:30 pm. If you have the right to fuck like noisy animals, then I have the right to play 'Yakety Sax' at a similar volume level. Them's the rules.