Neverwinter Nights could be another option, if you or your DM has a copy available. Open up the Aurora toolset, select the appropriate sound files, turn the speakers up. Given the massive amount of sound files in the program, you could also easily switch to (say) sewers, or inside a tavern, or whatever. Most of these files can be set to "continual loop", so will play until you decide to switch or stop them.
The one challenge is that you may have to play the files directly out of the toolset. They're not in handy .wav or .mp3 format, although I'm sure there are utilities available which could convert them.
