I have had a lot of exposure in my 50 years, from Concerts, to 155mm Howitzers a hundred foot away, the worst was firing 3 shots from a muzzle braked .458 win mag in the field without plugs (ringing changed pitch for each shot THAT cant be good), plus countless thousands of rounds of full and semiauto fire, from 17 yo on, throw in the Steam turbines, helical and recip compressors, 1000 hp pumps etc, I really need to baby them to keep whats left.