I’ve mentioned this before, but I believe it is the HEIGHT of disrespect, and a //form of passive aggression, to not wear one’s hearing aid/s, unless home alone. One theory is that your mom is afraid strangers will think she is old or infirm if they see she’s wearing a hearing aid. I remember that feeling from back in my 30’s when Igot my first aid. After a while I adopted a different-but-still-cool haircut. Perhaps your mom should talk to her hairdresser. Barring that, it’s time for a family intervention. Or, each time she says “What?”, refuse to raise your voice except to tell her to please put in her aids.
Remind your mom to clean her aids every night before she goes to bed. This will keep her molds from getting mouldy and leading to an ear infection. I favor “Audiologist’s Choice” hearing-aid spray. Spray it on a tissue first, not directly onto those pricey electronics.