When goats come up to the Nofence boundaries, the collar will emit a beep. The beep will start at a low tone that rises gradually as long as the goat is outside the Nofence boundary. The goat will recognise this tone scale, turn, and go back to the grazing area to avoid an electric shock.
The illustration shows normal behaviour when the goat goes out of the grazing area, responds to the sound, turns, and goes back into the grazing area.
For the electric shock to be emitted, the collar MUST have played all tones in the warning field. This is because it should be recognisable and predictable for the goat. It takes a minimum of 5 seconds and maximum of 20 seconds to play the full scale. The scope of the warning field depends on the speed of the goat as it leaves the grazing area, but in the majority of cases this will be approximately 3 metres.
To turn the sound off and avoid the electric shock, the goat must turn around and go back to the grazing area.