I was thinking about it, and it may not be the actual noise that bothers him. The fireworks in July didn't bother him, and neither did the parade (firetruck sirens, marching bands, and all) that recently went by our house. It may be the vibrations. We are close enough to the base that our house actually shakes enough to knock the pictures and stuff off of the walls (we actually quit hanging photos on our walls because we had replaced so many frames).
I'm still going to try some of the suggestions and will definitely figure out a new schedule for him. Thanks again.