Some tips to use the dog whistle: Adjust the pitch & blow the whistle to your dog. Even dogs can't hear all frequencies. Wait until he is asleep and gently blow on the whistle. Your whistle has a nut and screw that adjust the frequency when turned. Continue testing until your dog perks up. You will then know you have reached a frequency he can hear. Use the dog whistle with varying sequences to train your dog. For example, one long burst can mean "come", while a series of short, staccato bursts might mean "sit". Keep your whistle commands consistent and your dog will always know what you expect of him.