i have these 3 things too, it's pretty awful so i'm really glad he has someone to help.

bose "hearphones" are unfortunately not in your price range, but maybe you could budget for them down the road? i literally just got a pair about 2 weeks ago, and they are proving invaluable in loud settings like restaurants.

the other thing that makes my life more pleasant are disposable foam ear plugs. i buy them by the hundreds and keep them in various canisters like these when i leave the house.

I use these.

 https://www.amazon.com/dp/B00SFIRJK8/ref=cm_sw_r_cp_apa_i_TKuMDbXXQAT1P