Nanook has been loosing his hearing for a few years now, as well as his eyesight. Luckily when he was younger I trained with both vocal commands & hand signals.
When his hearing was first starting to go he would get scared more easily when I would pet him or the like. I think now he's adjusted to it a little more. I do stay consistant with what I do which I think helps. For example, if I pet him when he isn't looking, sleeping or I can NOT get his attention any other way, I gently tap him on the same spot in his behind with just one or two of my fingers. I then wait for his eyes to open, then I make sure he see's me. (consistancy helps immensely with any training, especially so when you are dealing with any type of disability).
Obviously he is not allowed outside off a leash and/ or unsupervised.

I am sorry I am a little strapped for time this morning, I'm trying to squeeze in as much PT as I can before I run out of time. lol If there is anything else you need to know, want to talk about, etc, please by all means let me know, reply here or PM or email me.