Senior dog going deaf; my loud talking to him is startling my toddler

Any tips on those that have had a dog losing it's hearing? It started about 6 months ago. He is a 12 year old Boston terrier Chihuahua.

My daughter is not his favourite. He is her world, she is absolutely obsessed, but he is old and just wants to be left alone. I make sure everyone gets their space with a fence separating large rooms so we are all together but also he can nap in peace on his bed during times she just wants to run around causing havoc.

I notice now I have to obviously raise my voice to talk to him. Not in a mean tone, but I'll ask him like 3 times about going to the bathroom or to follow me and he just doesn't hear me. I am now talking so loud to him it's startling my daughter sometimes. I don't want her to think it's normal to be so loud, especially to animals, but I can't not talk to my dog? He's 12 and stubborn.. I don't see him learning new hand signals.

Any tips?