Missed this the first time around and not sure how relevant it is to her particular sensitivities/hearing loss but I'll share in case it helps.
A few years ago I ruptured an eardrum which basically meant I was deaf in one ear while it healed (it took a couple months over which my hearing improved slowly). The first few weeks when I had no hearing were quite an experience though. Any situation where more than one person was talking was impossible for me and even slight background noise made hearing a person very challenging. We went to a small dinner party a couple weeks in and I had to leave, I couldn't hold a conversation and I quickly had a pounding headache. Having experienced that I wouldn't be surprised if a person with hearing loss would avoid noise, especially if they were expected to listen or have conversations.