The most quiet room I've ever been in was in the middle of a cave in southern Indiana. The guide turned his flashlight off. You couldn't see or hear a thing. My husband said that guides do that to give you an idea of what it's like to be in total darkness and no sound. It was freaking me out. In all fairness, my husband said that, that particular guide had his light off way too long. It was a kid and I think he was trying to scare people. Well...it worked. but I'd never let on to him that it did.