I'm in almost the exact same situation as the man you describe although I've never had hearing in one of my ears instead of having lost it very young.
I find it amazing that they guy would want to talk in the car while driving. For me, it is really kind of a painful to do it as I know I'm not getting everything and I'm trying not to get us killed.
Still, some of the things you mention are really overkill. Yes, it's hard to understand in loud restaurant, but that's true for anyone, granted more so for him. As for the other things you've mentioned, "cannot enjoy any of the sounds of nature, cannot have a deep conversation, sit around a bonfire with friends and talk, cannot sing a song on the radio, cannot go to/have dinner parties without him feeling left out, cannot tell each other jokes (because they're misheard or misunderstood)." This is only partially true. He can have a deep conversation; he can sing a song if it is a song he has already heard it; he can go to parties without feeling left out(this is his issue); he can understand the jokes as long as you look at him so while you are going to have issues with him it's not all as bad as you make it seem. Don't think you know how he feels because you don't, it may be perfectly OK for him to NOT hear everything. There are plenty of times he is going to enjoy being at that campfire in spite of not hearing everything. Unless you are dealing with someone who has chronic depression most HoH people are not as you describe. Afterall, he's lived this life and should understand it by now so I'd give him some credit.
You've got to be patient with this relationship, but trust me there are good times as well. And, since this is his first relationship it can't be easy. He's never had to deal with another person in his life before and that is a big adjustment.
