An audio signal interpolation device is presented, including an input unit for receiving an input audio signal, a phase splitting unit for splitting the input audio signal, a high range interpolation unit for interpolating a high range component into the signal, a phase combining unit for combining an in-phase component signal with a differential phase component, a high-pass filter for high-pass filtering the audio signal from by the phase combining unit, a delay unit for producing a delayed audio signal, and an addition processing unit for adding the delayed audio signal to the audio signal output from the high-pass filter.