What a terrible situation. I'm so sorry for your sister's plight.
I have not heard of hearing loss with
ALS, but I have had double vision while reading since the beginning of my symptoms, and it is steadily worsening. No one has been able to explain it. They say that
ALS does not affect the senses, but obviously, in some cases, it does.
I pray you find an answer to this, and doctors are able to reverse it.