Abstract: Random audio signals are converted into sine-waves of corresponding frequency and duration, and harmonics are derived from the sine-waves. The harmonics are controllably attenuated and selectively inverted and combined to form an output signal. The conversion of the random signals is effected by squaring the same to drive a Schmitt trigger which feeds into a levelled integrator which leads to a diode function generator. The harmonics are generated with the use of four-quadrant multipliers.