If I ever end up in that situation, where I am "locked in," I'd request that someone at least play a variety of radio stations for me so I wouldn't go completely and utterly insane, even if they had no way of knowing whether I could hear it or not.
I don't know a damned thing about it, but I wonder how much consciousness one would have in such a situation, even in the most optimistic scenario. Even with brain activity and functioning senses, I feel like you'd still drift into a sort of dream (or nightmare)-like state of altered perception. Hell, when I take a nap in the afternoon, I end up in a fog that doesn't clear until I splash some cold water on my face. I can't imagine what it'd be like without the ability to move or properly gauge my surroundings.
Edited, Nov 13th 2012 3:33pm by Eske