Patent ID: 8532801

Claim:
A method of processing a digital audio signal having a sequence of samples, the method comprising the steps of: using an extreme detector for detecting every extreme value in an audio waveform represented by the digital audio signal, the extreme value being either a maximum value or a minimum value; using an inter-extreme sample number detector for detecting a number of samples in time positions between time positions of two temporally-adjacent samples among samples representing respective detected extreme values to get a detected inter-extreme sample number; using an inter-extreme difference calculator for calculating a difference between the detected extreme values represented by said two temporally-adjacent samples to get a calculated inter-extreme difference; generating a corrective value in response to the detected inter-extreme sample number and the calculated inter-extreme difference, the generated corrective value being updated each time a new extreme value is detected; designating ones among samples in response to the detected inter-extreme sample number as objects to be corrected, the designated samples including at least (1) a sample adjacently following the older of said two temporally-adjacent samples, (2) a sample adjacently preceding the newer of said two temporally-adjacent samples, and (3) a sample being one of said two temporally-adjacent samples; and correcting the designated samples in response to at least one of (1) the currently-generated corrective value, (2) the previously-generated corrective value, and (3) a generated corrective value next to the currently-generated corrective value.