SOUND ELIMINATOR FOR RADIATED NOISE AT OPENING PART

摘要

PURPOSE:To stably eliminate a noise radiated from the opening part of a sound insulation cover. CONSTITUTION:Error microphones 26 and 28 are classified into a 1st error microphone and a 2nd error microphone and the filter coefficient of an adaptive digital filter 36, 38 is updated by a controller. Namely, a filter coefficient for minimizing the output signal of the 1st error microphone is calculated at some sampling time according to only information regarding the 1st error microphone and the filter coefficient of the adaptive digital filter is updated with this filter coefficient. Then a filter coefficient for minimizing the output signal of the 2nd error microphones is calculated at next sampling time according to only information regarding the 2nd error microphone and the filter coefficient of the adaptive digital filter is updated with the calculated filter coefficient.