My friend who owns a Spaniel has a 12 yr old dog that lost most of her hearing last year. She had the same problem. I started noticing how she was whining one day and my friend ignored her. I asked why she didn't take the dog to the vet as it seemed in pain. That's when she told me that the vet said a lot of dogs going deaf or completely deaf do this, and theyalso bark. It seems that the dogs reassure themselves in that manner since they feel the vibrations and hear their own voices. Now my cousin's Bichon is doing it and she says the same thing.
But I would definitely say to bring her inside near and dear for the rest of her days, A dog needs to be with it's human friends, not alone in a doghouse.