Amanda, I was just reading something the other day about how you can train your dog not to bark the way yours does. Based on what I read, and your story of what the dog is like when out for a walk with you . . .you must already be halfway there with the training.
(As an aside, I saw something on the street the other day, that I found quite amusing. I was in the downtown core, highrises all around, and around the corner of an office tower, came a woman walking a dog. She had the leash cinched up tight and was keeping great control over her dog, which was prancing along in exactly the right position. Then behind her came another person, with another dog, and then another, and another, and another . . .each owner had a different breed of dog, large dogs, small dogs, large French Poodles, Great Danes, Scottie Dogs, Dashund's . . and on and on it went. I gawked and then laughed out loud as I walked away . . .must have been a dog and owner training class because it is a very odd place for a dog walking club.)