To use a dog whistle to stop barking, interrupt the dog from barking by distracting him or her from barking with the sound of the whistle and then rewarding quiet behavior with a treat. Consider training the dog to understand the "quiet" command to stop barking with tips from a dog trainer in this free video on dog obedience. Expert: Nancy Frensley Contact: www.berkeleyhumane.org/ Bio: Nancy Frensley is a certified pet dog trainer. Filmmaker: Sam Lee