Theo,
To answer your question about your fried, there is probably no reason at his age he would or should stop shooting. Hearing damamge is defined into two categories, Conductive hearing loss (bone decay or damage to hammer, anvil or stirrup) or Nerve Damage. Medically speaking nerve damage is irreversible, and conductive hearing loss can have positive gains through surgery. Tympano plastoidectomy is a procedure where they can place a prostetic device ( like a plastic hammer or stirrup) after removing your original equipment hammer and stirrup. also behind your ear the crannium normally has a honeycombed area that helps conduct sound,and as we age the honeycombed area decays and fills in the honeycomb area and sometimes the clean out(drill out this area to restore its ability to conduct sound.
If your friend uses a good set of ear muffs, he should be fine, I protect my good ear when shooting by using an earplug style device plus a good set of ear muffs.
I have had 3 surgery's on my left ear, conductive loss initially, and the doctors twice put in prostectic devices which each failed about 18-20 months after surgery the last time they said there wqas nothing left that they could attach the new prostetics too, and leaned the hammer up against the ear drum and provided me with a hearing aid. When they put the new aid into my ear and turned it on there was a lady and her son sitting a good 3o feet away and I could actually hear her whispering to her son they are phenominal pieces of technology and like someone else said they get better every year. Good luck.
