An audio processing circuit, audio unit and integrated circuit and method for blending are described. The audio processing circuit comprises: a time-to-frequency domain circuit configured to convert a primary audio signal and a secondary audio signal in a time-domain form and output frequency spectrum representations thereof; a cross-fade magnitude circuit configured to obtain a cross-faded magnitude spectrum representation from the frequency spectrum representations; a cross-fade phase circuit configured to obtain a separate cross-faded phase spectrum representation from the frequency spectrum representations; and a frequency-to-time domain circuit configured to receive the separate cross-faded magnitude and cross-faded phase spectrum representations and output a time domain signal.