Do high frequencies also bother you? or mostly the low ones? I don't think low ones impact him (from what I can see) but definitely no questions asked the high pitches do. I see how individual everyones experiences are yet so much commonality with the reactions to whatever the "triggers" may be.
Occasionally higher frequency sounds (leaf blowers) can irritate me, but nothing compared to lower frequencies like booming bass from audio systems, or souped-up muscle cars or trucks idling in a nearby parking lot. Such sounds literally go to my stomach.