So sorry the racket is maddening. I've experienced that too and moved once because of it. There is also a collar a dog wears that emits citronella (harmless to dogs) when they bark. It works and will teach them not to bark unless someone is at the door. I had to use it with my dog when I first moved in because someone complained about her. I had just got her and did not realize she barked when I was gone till the manager told me and also told me about the collar. Maybe you could tell your neighbor about the collar. It actually trains the dog not to bark when the owner is not there. I don't use it any more because mine has learned from the collar and no longer barks when I am gone. Best of luck to you with this issue.