teach your dog to nose target the phone every time it rings.
teach the nose target
ring the ringer and give the target command at the same time. keep reapeating this a whole lot in different rooms in the house.
periodically test it by just ringing the ringer.
when the dog makes the connection and targets without the verbal cue, give them a jackpot reward and repeat this exercise in different rooms in the house.
I'm so doing this with Wally.
And while I'm at it, I'm going to teach him to bark at sounds like the oven beeping or the kettle going off, by switching the cue and sound (hopefully it'll work - seems like the same method)