After 6 years of dealing with an unpleasant neighbor and his animal farm menagerie, we purchased a dog silencer.
Within 2 days we experienced a reduction in barking, within a week we actually slept through the whole night.
We were so impressed, we decided to get a second one and life quality drastically changed. The norm now is silence!!!
We also found out that the device doesn't work on birds (including chickens and pheasants), rabbits and cats.
From our experimentations we learned that two silencers work better and quicker than one, especially if you have more than one neighbor to deal with.