It’s definitely your place! I am 65 and I have severe hearing loss. I have had a heart aid for 10 years now, it doesn’t bother me at all, my dad was hard of hearing and as he lived in France, we relied on telephone conversations a lot but I couldn’t get much out of him as he couldn’t hear me and also he had become socially withdrawn. I remember telling him he needed a hearing aid and he had the same reaction as your dad so I said to him: You wear glasses Dad , well it the same and it shows less, you would never think going out without your glasses!!!He eventually got some hearing aids but them the problem was making sure he wore them all the time. People would need to know , I know that now!!! that hearing aid although being helpful are not perfect, it doesn’t replace totally your hearing but it’s important to wear them so your brain re-adjusts otherwise it becomes lazy. I find that with mine but before I got the hearing aid I was starting to not go out to the restaurant ... with my friends. It’s still not perfect but at least I can hear the birds sing!!!!! And my grandson! Mine are nhs so they’re free. I was told that the private ones are more or less the same. Work on it with your dad and good luck , he can’t be more stubborn than my dad and my father in law!