I can add from experience that when you are the one doing the shooting there really is such a thing as auditory exclusion. You hear the shot or shots but the sound seems muted or of little consequence. It just doesn't grab your attention. A therapist once asked me, "what did it sound like?" I answered back not trying to be funny, rifle fire, which was the truth. My buddies laughed at the debrief. I guess he was making the point that some hear no sound at all, not my case at all.
You really are on another plane. The sound is nowhere as noticeable as when someone starts shooting around you at the range just as you are putting your ears on. I believe adrenaline and fear have a lot to do with it.