I am disabled and need a mobility aid, a different type, but I realised that being stubborn/nervous and not using it was causing me and my loved ones more problems (ie. It is a very obvious symbol that I have a disability to help myself and others when I'm in public, and it means I can navigate better without someone having to guide me etc). But I spent a lot of time rejecting it, making things worse for everyone.
In your case, I'd say he is being selfish and it may come from fear, or stress, or another justifiable reason. But you're free not to date him because of it, I wouldn't want to shout constantly either. I would be direct with him about that if you genuinely like him.
Hearing loss is linked to a higher risk of dementia too, I think? Which would also worry me if it became a long term relationship. Or if his hearing gradually gets worse and he STILL refuses aids. It is a topic for legitimate therapy, I've had to have it myself to get to grips with changes.
However, men who totally refuse help, solutions, and adjustments, well, to me that's a red flag.
He hasn't looked properly into ways of making his own life fundamentally better, but again, that is his choice .. All you can do is decide what you'll tolerate. It's not remotely ablist to "reject" him, because it's based on his stubbornness rather than simply because he's deaf.., But people on here will probably accuse you of that..but often they don't know how truly frustrating it can be living with sensory disabilities, either in yourself or loved ones. Flexibility and common sense has to come into play to get the most out of life with disability.