I've had a lot of elderly dogs in my life, many of them were completely deaf by the time they were put to sleep.
I found that the higher frequencies go first, so doing stuff like whistling...doesn't work as well as a low toned call to the dog would do. But, eventually that didn't work either, so vibrations can help...as far as getting their attention.
Even old dogs can learn hand signals. I use to put my fingers to my lips to indicate food, and would lower my hand and come here was just gestured using my hand, as if they were to follow me. To tell them to lay down, I would just point at their bed. Of course, these hand signals were taught as the dog was going deaf and I don't recall it being much of an effort to teach them or for them to learn.
Just be sure as your dog's hearing gets worse that you try to use vibrations and such to let it know you are near by...they get startled really easily when they can't hear and you suddenly come up behind them and pet them or something. I started making it a habit of approaching my dogs from the front so they could see me coming and know I was reaching out to them.
Hopefully, your dog won't go completely deaf, but know that even if that does happen, they can still have a very good life and will still interact with you and others. I don't think dog's dwell on it that much...they adjust...and it's we humans that feel their loss more than they do. Just my 2 cents. : )
Stormy