OP here:
Thank you for your responses. The latest regarding my information and the recovering victim:

Regarding hearing damage from airbags. One friend has done some reading and tells me that hearing damage from airbags is not unknown but is considered a very minor likelihood over the range of vehicle accidents.

I think I was in error in my own thinking of the damage as being the result of over-pressurization. What is going on is that deploying airbags are explosively loud. (I still wonder what if you're in a Prius with four people and you hit a wall and all the bags go off).

I was rear ended by a car on the highway about ten years ago. We were both in new cars. My airbags did not inflate. The girl behind me did experience it and she was crying from the experience.

As to my musician friend, she is probably going to be fitted for hearing aids for the near future and hope for the best. She's been told that hearing aids are mostly to make out conversations, but she knows a hard of hearing harpist who says that they can be tweaked for musical needs.