How much is too much??!!

OK, so the question for the night is. . . How much loud sex in an apartment is too much?

Let me explain. We apparently have a neighbor in our apartment building who enjoys her sexual activities- A L O T!! and VERY loudly. My DP heard them going at it the other night when it was really warm outside and she could hear them for a very long time through the open windows. We wondered who it could be . . .

Then tonight as we are walking down the hall to our apartment we hear it again-and when I mean loud, I mean screaming, moaning, things crashing and banging . . . I put a note on their door letting them know that their extremely loud sexual activities were irritating to those around them. I am sure they will laugh it off, and keep the note for posterity.

But seriously, are we just stuck with them? Do we have any recourse? Is that OKAY to be subjected to that? I know I have issues with sexual stuff, but I would so much rather not have to hear it that close to me . . .

I don't know-just my thoughts from the peanut gallery.