That's intended behavior for using noclip and going too far out of bounds. It happens if you exit a certain zone you're never supposed to leave. Not the playable area, but a slightly bigger bubble around it.
It may also happen if you're using god mode and you're going to areas of the map that would insta-kill you, like when you haven't bought the door(s) to it yet. Unopened areas tend to just kill the player if you happen to step foot into them via exploits/etc. May differ from game to game though, it doesn't happen on IW for example.
In short though, no, there's no way of stopping the SFX bar turning down the specific volume slider or just never going too far out of bounds.