Back to the OP, Atlanta has a noise ordinance.
http://www.nonoise.org/lawlib/cities/atlanta.htm
The following specific acts are declared to be in violation of this article:
5) Animals. The owning, possessing or harboring of any animal which frequently or continuously howls, barks, meows, squawks or makes other sounds which create excessive noise across a residential or commercial real property line or within a noise-sensitive area. For the purpose of this article, barking dogs shall include a dog that barks, bays, cries, howls or makes any other noise continuously for a period of ten minutes, or barks intermittently for one-half hour or more to the disturbance at any time of day or night regardless of whether the dog is physically situated in or upon private property.
And here
http://www.peachtreebattlealliance.org/id28.html
I have to think that if multiple neighbors are persistent, you will be able to get this dog impounded or his owners fined.