Our instructions were to stand 100 yards back, hands cupping both ears and mouths open when the MWs were firing. Nobody cared about the pakkapakkapakkapakka from the Co-ax.
All fine and well until some dweeb forgets how to COUNT and the ammo party goes up to the Tanks on the firing-point and there you are, loading Inert w/Tracer and FUSED HE rounds (WITHOUT clips) into your Tank.... and the guy in the next machine, 10 feet away, mashes the Magic Button. BIG blast, berets off, eyebrows singed and the Sergeant comes running up to you and screams at you. You can see his mouth opening, so you nod a 'yes' (one NEVER says 'no' to a Sergeant, they being appointed by God Himself) and he keeps on screaming and you can hear someone, a very long way away, saying very quietly "Can you hear me?". Your head rings for a while and your hearing comes back over the next day or so but, a few years later, you find it impossible to listen to a conversation with any music going on, things like that. A few years after that, you find yourself watching people's mouths very carefully when they talk... and that can get them PO'd at you because nobody likes to be stared at!
Just one of those things.
But thanks for the info. Gets any worse and I just might use that.