ACTIVE SILENCING DEVICE, AND ACTIVE SILENCING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an active silencing device capable of efficiently reducing noise.SOLUTION: An active silencing device according to an embodiment comprises: an error microphone for converting sound including control target sound to a first error signal; a control filter for creating a control signal for cancelling the control target sound according to a control characteristic; a first control effect estimation filter for converting the control signal to a first signal according to an estimation secondary path characteristic obtained by identifying a secondary path characteristic in advance; an estimation noise signal creation unit for creating an estimation noise signal by subtracting the first signal from the first error signal; a second control effect estimation filter for converting the control signal to a second signal according to a process secondary path characteristic obtained by shortening a delay included in the estimation secondary path characteristic by a time obtained by multiplying a period T of the control target sound by a constant m, where the constant T is a positive integer satisfying T×ma; and an update unit for updating the control characteristic so as to minimize a second error signal which is the sum of the estimation noise signal and the second signal.