For elite players who don't want total silence but just reduced volume, here is an advanced snippet for your pain.cfg . This binds a key ( F9 by default) to toggle between normal, quiet, and silent modes.
If you’ve ever been in a clutch situation, listening for the faint sound of a defusing terrorist or the footsteps of a last enemy, you know that extraneous noise is your enemy. The default "pain" sounds—the groans, gasps, and death cries your character makes when shot—can mask critical game sounds.