Dang it, y'all locked the thread!
Brian, I dunno if little ears are more sensitive than adult ears or not, but hearing damage is not reversible and accumulates over our lifetime. They need to have their little ears protected - from loud TVs, music, etc, not just firing impulses. Age-related hearing loss is also driven by genetics, not simply environmental factors.
Off-the-shelf hearing protection is NOT one-size-fits-all. I used to take my kids in to the Health Clinic and have them properly fitted for hearing protection by an audiologist - well, except for our deaf daughter, LoL! Before taking kids shooting, I strongly recommend having them fitted for ear plugs about each time they out-grow their shoes. One side benefit of doing that is when my now-older kids go to a concert or fly, they wear earplugs...
FWIW, properly fitted and worn triple flange ear plugs offer the most attenuation of high frequency impulses, muff claims notwithstanding. Belt-and-suspenders approach is plugs and muffs.
Ever stood next to C4 or TNT going off? Tank main gun? Fired 90mm Recoiless Rifle prone? Now THAT's loud! Makes a shotgun seem less than finger-snapping.
BTW, Wyoming jackrabbits sneer at body hits with a 22 lr. You should invite Bountyhunter down there to show you how it's done... as long as he agrees in advance to eat what he catches... <grin>
Tom