How can dog whistles be used to stop barking?

Dog whistles emit high-frequency sounds that are not easily heard by humans but can be heard by dogs. By using a dog whistle to make a specific sound when a dog barks, the dog can be trained to associate that sound with a command to stop barking. Over time, the dog will learn to stop barking when it hears the sound of the whistle, helping to control excessive barking behavior.