Mark,
I'm a musician so the hearing protection thing is important to me too. For me a have a set of custom earplugs that cut out 15db accross the whole range of sound. I can still converse or rehearse a group with them in. They work well when riding or mowing the lawn too. Ironically anyone who can fit hearing aids should also be able to get those.
For the little one: as a dad myself, I can tell you the most effective thing is "Whatever he will leave in/on." They make kids sized earplugs meant to eaqualize pressure when flying called Earplanes. Get them at your local drug store. These are the only ones that my 8 yo daughter will keep in. They are the rubber kind with baffles (like some shooting plugs)--kids don't like the feel of the foam ones because they expand and cause pressure.
Good luck--John
