When you're really amped up (adrenaline), you aren't going to notice the "bang" at the time, for the most part. It'll still do damage to your hearing of course, but that'll probably be the last thing on your mind.
Basically, where a sound may be debilitating or distracting when you're not amped up, it'll probably just sound like a pop when you're turned up to Eleventeen!
For instance, the incident I was involved in years ago where I had to draw my pistol... I didn't have to fire, thank God, but there are times when I still dream about that incident and I can remember very specific details. What the BG was wearing, smells, details. The funny thing is, most of the details I recall were only the things in front of me. Like I had tunnel vision. I saw/remember very little of what was going on to the sides of me. Seriously, it was if I could smell they guy as well as see the stubble on his chin. In my case, I feel that my body was totally focused on the threat, everything else was pushed aside. Hopefully, if I ever have to draw my weapon again, I'll have a broader scope of recall. (Not that I ever want to have to draw it again, but if I do, I hope I don't get so tunnel focused.