I and my FIL have the same issue with cacaphonous loud random noises. Jr has the same issue.
What we are doing with Jr is slowly acclimatizing him to cacophony by taking him to the mall, arcades, sports events, etc. When he shows signs of stressing, we leave. He can now spend an hour at the arcade and can sit through the first half of a football game outside. We'll try a pro baseball game next week. He still cannot stand touchhdown celebrations at our local sports bar, so I have to put my hands over his ears!!!
We've taken him to the range at the ranch and skeet practice and he is now used to that. He still has a problem when the horses first come up and stand around blowing.
What has helped IMHO is that we got him his own piano and a drum ( hollow cardboard box ) to beat on.
