My wife will tell you I HATE barking dogs, and we now have 4! My sister-in-law introduced us to a little gizmo called "Pet Agree". It is a training aid from a pet supplier in Dothan, AL called Jeffers. She uses it on her Chihuahua, who really barks, almost when anyone moves! So we got us one and use it occasionally on our "herd". The instructions says it works up to 20', but I used it over the fence on a neighbor's dog, which was outside the 20-feet, and I'm thinking it worked.
It was only $23. Below is the link to their website. There is a birdhouse model on page 1, along with several other models, with a greater range some of you might consider. The "Pet Agree" we bought is on page two. We will certainly bring ours when hopefully we move to TV in 18 months. Might even take it to the town squares!
Good luck. I think some people just don't hear their dogs barking; BUT, I sure do.
http://www.jefferspet.com/training-b...10023/start/0/