Cesar Millan addressed a similar case on the "Dog Whisperer." The dog barked like mad at the toaster and the microwave. Cesar taught the owner to "claim" the kitchen and the appliances. I don't recall exactly what that entailed and how it desensitized the dog, but you can check it out on Cesar's DVD:
Dog Whisperer with Cesar Millan, Cesar's Toughest Cases DVD - National Geographic Store
I found it at my local library.