Definitely should be! You'd just need a sound file and some way to trigger it in the inn. (An activator or a script, back in Morrowind, but, of course, we'll have to see what Skyrim's CK will look like.) Certainly, you could dig up or make an appropriate sound file now, I would think, while we're waiting for the CK to be released, and then it's just a matter of working out how to integrate it into the game.
If you do make this, I'll download it. I agree with you, the inns sound almost creepily quiet.
Edit: CK, for Skyrim, not CS.