Time for a walk!
It’s not just the sounds of someone saying, “let’s go for a walk!” that can trigger an excitement response from a dog. In this person’s case, whenever she was chatting with her sister over the phone, the dog took it to mean it was time to leash up and head out the door.
In the past, she and her sister would chat while taking the dog for a walk. The sounds of the two women speaking had become ingrained in the dog’s mind to mean that they were going for a quick walk around the neighborhood. We hope the dog wasn’t too disappointed waiting for a walk that was not going to happen.