When a barking dog is in the area covered by the Petsafe Bark Control System, an international microphone picks up the sound. The device then automatically emits audible ultrasounds for dogs, but inaudible to most humans.
Surprised by this high pitched sound, the dog should stop barking. Over time, the dog will make the association between his barking and this unpleasant sound. When the dog stops barking, the ultrasound emission also stops. The device is effective up to 8 meters.