Hi I'm Nancy Frensley, I'm the training manager at the Berkeley East Bay Humane Society in Berkeley, California. And I've been asked how to stop a dog from barking using a dog whistle. Well I'll tell you, usually I use a dog whistle to teach my dogs to come. I use it by blowing and this is a silent whistle that I keep on my key chain. Blow it and give my dog a treat. Ok. What does the whistle do? The whistle because it's a high pitched sound in this case it's not completely silent gets my dog's attention and that is all I really need to do to use it to keep my dog from barking. So if every time my dog stops barking, I go and then give my dog a treat for turning towards me I have started the conditioning process of interrupting the barking sequence at a certain point so that my dog is quiet after that point. And after I have interrupted the behavior ,I then reward quiet behavior. My dog is quiet ,there it is. So the whistle to teach, to work with the dog to stop a dog from barking is simply an interrupter. And frankly what I find easier to do is to just teach the word quiet and reward my dog for being quiet. So if I'm out or somebody has come to the door I hear knocking and my dogs go whoo whoo, I'll say quiet give them a treat after that before long quiet means oh come over to me. And your dog learns that they get rewarded for quiet behavior that is not barking. Barking is a very sort of amped up excited state of being. And once you blow the whistle and interrupt it. Or say quiet and interrupt it your dog drops that amped up feeling and gets rewarded for quiet behavior. Now if you're going to use something like this to create quiet behavior you have to use it each and every time your dog is likely to start barking. And that's where most of us people fall down on the job.