What is Ultrasonic and Sonic sound?
The Dog Silencer Pro generates two different sound frequencies you can switch between with the turn of a dial. Sonic (audible) sound can be heard by canines and humans. Ultrasonic (inaudible) sound is outside the hearing range of humans but is extremely high pitch and annoying to canines. The sounds are completely humane and painless to the dog. We recommend using ultrasonic sound unless the dog does not respond, then switching to sonic.
