1. A spatial adaptation method for providing long term symmetry among a plurality of microphones, comprising the steps of: calculating a magnitude ratio (MR) by computing the ratio between a first energy representing first group of one or more near-field microphones and a second energy representing a second group of one more far-field microphones, wherein the spatial adaptation method provides self-calibration for microphone matching of large variations without any situational assumptions to lower manufacturing cost and complexities.