This was not the first time I'd had a conversation with someone whose partner or parent had hearing aids and never wears them. I got to thinking about it...maybe people think it's like glasses. The expert tests your hearing, and then programs the aids to your hearing profile, you go away, and that's it for awhile.
Trouble is, it ISN'T like that! It's more of an art, a cooperative effort, and it is an effort. It takes time, attention, and work. Otherwise they are uncomfortable, which may be felt as physical discomfort when it is actually discomfort from things sounding subtly weird or harsh.
I've had hearing aids for at least 25 years, and I've gotten more aware and demanding. Now I like trying out new ones to see how the technology is progressing. (Yes, you have to buy them, but the ones i try usually have a generous trial period of several months, and i've gotten extensions).
When I'm trying a pair, I have to of course go to various restaurants, a movie, concert, lecture, meetings, parties... try them in every setting. A trip is great, to see if finally I can understand the announcements in the airport...nope, still can't even now. I have to nudge someone near me and say "what did they say? what row is boarding?"
So what I do now is make a chart or spreadsheet of PLUS, MINUS, and INTERESTING and during the day I add things like "couldn't hear man with deep voice very well" or "traffic sounds too loud" or "aids screech when i hug someone" or "i could understand the movie mostly!" or not, etc. Then go back to audiologist and tell her. She'll tweak them, then you go home and do it all again until between the two of you they are as good as you can get them.
Or else she recommends trying a different brand... yes there is a difference in the sound of a brand, kind of like stratocaster vs gibson if you know what i mean.
So all i'm saying is if your partner isn't wearing them, you'll have to drag them around on outings and quiz them about the specifics of what they are and are not hearing, until they get the idea and start to believe that they are part of the solution and things can get better. Otherwise, we deafish folks just start turning off our attention and smiling mysteriously when people are talking, and we don't even realize it!