Sound plays a big part for me in game. Sometimes, I want to pwn without hacks, so I turn them off, and I usually listen... and once I hear footsteps, I walk side to side, where it gets louder, I run in and burst click. Usually, I've got no chance, since everyone sprays... But, when the sound is weird, I die a lot faster. It's sort of on and off... and mutes some sound effects and doesn't mute some others.