We all experience what our brains cobble together from some sensory inputs, saying "it wasn't as loud as a gunshot" is, at best, a meaningless statement, and at worst, utterly idiotic.

What the hell are you talking about about? An acorn hitting a car might be 50-80 decibels; a Glock 17 9mm pistol is 162 decibels, that's louder than a jet taking off. That is ridiculously loud, perception doesn't factor in at that point. If you can't tell the difference between an acorn and a gunshot then you are not properly tethered to reality.