I think getting an ordonnance from somebody is an essential for the first time, @Sandra_Eales . As is usual for these things, more is reimbursed with a prescription than without one. I got mine from an ORL but it wasn’t any better than a few words done by a GP - just something along the lines of “this person needs hearing aids” 
As far as vanity goes, I have behind-the-ear ones and no-one ever notices them - probably depends on how short your hair is!
Regarding 100% sante - full reimbursement by the state is only for the simpler hearing aids, so how much of anything more sophisticated is refunded depends entirely on the nature of your mutuel. A lot of them don’t cover hearing aids. However, it may well be that a simple one will be all you need… 