It would definately add a creepy suspense to the game, but how much that is needed, I do not know. I think it would make pking more interesting, harder, but more interesting indeed, maybe sound indicators in dungeons, like, you can hear vibrations, much like the spy vs. merc mode in Splinter Cell Chaos Theory, in which the mercs are able to hear loud, carelss spies with a vibration reticle. Sounds like a good idea. I'd like to see it expanded upon though.