Hi all,

I live in an apartment and my room has a hollow-core door, which is of
course miserable in stopping any noise. I'm looking to give it a little
better soundproofing performance, cheaply, without major modifications
to the apartment (e.g. replacing it with a solid-core door). I'm not
looking to completely soundproof it either, just improve that aspect a
little. I've heard arguments for and against putting foam as a backing
to the door. Another option I've heard was foam backed by sheet rock
(though I don't have a workshop, so making some structure, even one as
simple as this, would be more difficult... a simple material I could
tack on back of the door would be ideal)

Any suggestions are welcome. Thanks!
Andrew