Knock on the door and diplomatically ask them to turn it down a bit.
Obviously not while they're shagging, or else the response may well be less than civilised.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Tue 30 Jun 2009, 21:10, archived)

but,
It's the sound of them shagging that's disturbing him.
( mnb098mnb used to be here, Tue 30 Jun 2009, 21:10, archived)