When my character gets a headshot the volume of this is way too loud. I want to disable this headshot sound entirely or make it much more quiet. Is this possible?
No, as it currently stands there is no way of doing this. Modifying the volume of a single sound is not possible.
What you could do is changing the sound file in the game's vpk file, but that will get you blocked from pure servers, so you would only be able to join custom servers, which don't use