It's fascinating, at least to me, to observe my deaf dog Lily and try to figure out what visual clues she is using to tell herself to growl or bark or run. Now, if the other dogs are growling, barking or running it's pretty easy to suss out.
Tails are problematic-Greta's tail is curved. Cody has a magnificent tail, but a lot of nervous energy and ambivalence, so it's usually waving no matter what the situation. Prissy's tail is in a permanent state of asserting dominance.
Oliver's scruffy tail seems to be the one she watches for clues. His tail is the most fluent for expressing what is going on in the world of the hearing. It's also the biggest and easiest to spot after dark.
Now his ears, not so much. It's pretty hard to tell what movements are intentional and what is just flapping in the breeze-but the rest of the gang has very expressive ears.
Another interesting thing I've noticed is that the other dogs have clued in to the fact that Lily barks when she sees something she doesn't understand, which is to say she barks at a lot more things than THEY do. Anyone else's bark is usually given at least a look see by one or more of the guys. Not Lily's.
It will be interesting to see if she works out what is bark worthy and develops some street cred, or continues to vocalize. She is actually a month or so older than Oliver, but size and handicap has made her very much a follower-but not an unhappy one.