When I was in NTU (and that was a long time ago), couples are more "silent" and I don't remember hearing any moaning or anything. I do pet with my then gf but only when we are alone in the room,but never with my roommate around. But most roommates are very "automatic" and will leave the room when their roommate brought a partner back to the room.
Long time cohabit also have, but is really very vey rare during my time. More of the exception rather then the norm.
Can see high heels in guys' floor and guy's shoes in gals floor outside the room with door close... but no moaning noise !!
During my time, mostly couples doing it, don't have anyhow anyhow . Not sure about now.
Stories in the newspapers are always sensationalised.