Since 1992, I've worked with two guide dogs. Because my hearing was still good enough to benefit from hearing aids, I never had my first guide dog trained to perform hearing duties. However, my current guide dog has been trained to alert me to the sound of my name being called, the phone, doorbell, a knock at the door and the smoke alarm (inside my apartment and the outside hallway). She was trained by a local school who trains hearing dogs. The training was done here at my home and only took a short time to complete. One thing I was surprised by was the fact that my guide dog's guide work didn't suffer as a result of her learning additional commands. My guide dog is an extremely quick learner and has been trained to respond to commands in ASL. Now that I have CIs, I don't rely on her to alert me as much as I used to (except at night when I remove my CIs). However, since the training is still engrained in her, she continues to alert me to various sounds in my environment even though I'm able to hear.
DeafDoc1: I know what you mean about the dog being an "ice breaker." I feel the same way about my guide dog. Sometimes sighted-hearing people don't know what to say to me, so the dog is a good conversation starter. Granted, that's not the reason I got her, but it's still nice to know I can have something to talk about with people who may feel uncomfortable around the deafblind.