A sound processing circuit comprises a first input for receiving a first input signal, and a second input for receiving a second input signal. A first adaptive filter receives the first input signal, and an error calculation block calculates an error between the second input signal and the output of the first adaptive filter, and outputting an error signal. A second adaptive filter receives the error signal, and an output calculation block subtracts an output of the second adaptive filter from the first input signal to generate an output signal. The adaptation of first and second adaptive filters is controlled based on a magnitude coherence between the first and second input signals.