Its interesting about the gunfire...Army Cadets at school have a lot to answer for. I was firing .303.s with no protection for several years at school, and did a couple of weeks with the regulars doing battle camps etc. - not an Ear defender in sight.
A medical aged 24 revealed gun damage in both ears(worse in the left).
The Consultant even came back in clutching my audiogram with a big grin.."Ever done any shooting...303...right handed?"
Still got my Class One though, but I'm a stickler for ANR headsets and big ear defenders for walkrounds. I've got some 33db plugs for music and loud places...paranoid...moi?
I do wish that jets used light aircraft style voice activated mics, then I could use BOTH ears of my anr set and turn the volume down even more on the radios...