Here are some of the ways people in other rooms might react:
1) They chuckle and keep listening
2) They turn on the TV or put on headphones to drown it out
3) They get aroused by it
4) They leave their room to get away from the ruckus
5) They call security
If I were in this situation, I'd probably do #1, #2, or #4. It's amazing how some couples have loud sex unabashedly at hotels. At the very least, they could turn up the TV volume or put some music on to drown out the screaming and moaning. However, more daring couples might claim it's all part of the fun; to them, the thrill of getting caught makes the sex that much better.
What's your take on this? What would you do if you heard people at a hotel having sex? What if people heard you and your partner doing the deed?