It may very well be that they are hearing the other dogs in your neighborhood barking. It is a shame when the wrong person is unjustly accused. Years ago I had a neighbor who accused me of letting my toy poodle poop on her lawn. He was never allowed outside of our fenced back yard so that was totally impossible. I knew it was the dog across the street because I had seen him do it, but I didn't want to start any neighborhood brawl so I didn't tell her. I just assured her it was not my dog doing the pooping.

In my previous neighborhood I lived next to a nurse who worked the 11:00PM to 7:00AM shift. She slept during the day and consequently I was always paranoid about my dogs barking at any time of day. She never complained but I always brought them right in when they started to bark. It's so hard to keep everybody happy isn't it? Dixie Belle is right. It would be nice to be living on acres and acres of land with no neighbors nearby but unfortunately that is not usually the case. Good luck!