Description:Set the two oscillators to equal amplitudes, with the first oscillator at about 500 Hz. Slowly sweep the frequency of the second oscillator from below 100 Hz to above 500 Hz. For very small frequency differences the two tones fuse, becoming a single tone with beats. When the second frequency is near the second harmonic of the first tone (or vice versa), second order or quality beats will be heard. For arbitrary large differences in frequency difference tones will be heard; the strongest occurs at the frequency difference between the two oscillator frequencies. As the frequency of the second oscillator is changed the frequencies of the difference tones can be easily heard to change.