Audacity is used to generate the tones, 0.7kHz, 3kHz, 5kHz, 7kHz, 11kHz, 13kHz, 17kHz, 19kHz, 20kHz, and 21kHz with and without some amount of white noise. The signal from the Line Out connector of the motherboard is looped back into the line In connector with a cable, which is usually connected to the analog output of the Soft66LC4.
