There are times when I wish I qualified for a service dog, but right now, we aren't allowed to have a dog in MIL's house and I don't there are too many other people in the house.
I have more than just my hearing loss to deal with. I fall every so often and these days I am having more vision problems. The house is too small to keep my cane with me all the time.
If you want a dog to do more than just alert you to sounds, the dog is no longer just a hearing dog. If you have low vision then you can apply for a guide dog.