Dog whistles are a type of whistle that emit sound in the ultrasonic range, which humans cannot hear but some other animals can, including dogs and domestic cats, and are used in their training. They are used to train or command animals without disturbing nearby people, as they do not produce a loud, potentially irritating noise for humans that a normal whistle would produce. Some dog whistles have adjustable sliders for active control of the frequency produced. Dog whistles can be used in a variety of different ways, including:

• Recall training: Dog whistles are most commonly paired with recall training, as they are more distinct and discreet than a humans voice.
• Stop barking: Dog whistles can be used to stop barking, train basic obedience, or even modify specific behaviors.
• Hunting or herding: The high frequency emitted by dog whistles can travel far greater distances than a voice, making them a great tool for hunting or herding dogs.

It is important to note that dog whistles are not silent, as they emit a tone of around 35,000Hz, which is indiscernible to humans, but piercing to a dog. They can be helpful dog-training tools, as they can be used to give cues at a long distance or as a more consistent alternative to a verbal cue. However, before being introduced to a whistle, dogs should master verbal commands. It is also important to avoid using the whistle close to a dogs ears and to avoid blowing it at full strength, as noises to the top of the dogs ability to hear can cause pain if they are too loud.