PROBLEM TO BE SOLVED: To reduce interference between channels under active noise control.SOLUTION: A noise cancellation device comprises: a table TBL which stores coefficients representing transfer characteristics from a first speaker 21 to a first microphone 11, frequency by frequency, and outputs a coefficient corresponding to a rotational frequency of an engine, wherein gains of transfer characteristics from a plurality of speakers including the first speaker 21 to the first microphone 11 are compared, frequency by frequency, and the coefficient is determined based upon comparison results to have a value reduced by a first gain when the rate of the first gain to the total of the gains from the plurality of speakers to the first microphone 11 is smaller than a predetermined value; and a signal processing part Z which generates a first cancel signal CS1 for generating a cancel sound for canceling an engine muffled sound based upon the coefficient, a first reference signal EN1 and a second reference signal EN2 synchronizing with rotations of the engine, and an output signal output from the first microphone 11.SELECTED DRAWING: Figure 4
【課題】アクティブ・ノイズ・コントロールにおいてチャンネル間の干渉を低減させる。【解決手段】第1スピーカ21から第1マイク11までの伝達特性を示す係数を各周波数に対応付けて記憶しており、係数は第1スピーカ21を含む複数のスピーカの各々から第1マイク11までの伝達特性のゲインを周波数毎に比較し、比較結果に基づいて、複数のスピーカの各々から第1マイク11までのゲインの合計に占める第1ゲインの割合が所定値より小さい場合、第1ゲインを減少させた値となるように定められており、エンジンの回転周波数に応じた係数を出力するテーブルTBLと、係数、エンジンの回転と同期した第1参照信号EN1及び第2参照信号EN2、第1マイク11から出力される出力信号に基づいて、エンジンこもり音を打ち消すためのキャンセル音を発生させる第1キャンセル信号CS1を生成する信号処理部Zと、を備える。【選択図】図4
NOISE CANCELLATION DEVICE
ノイズキャンセル装置
2018-10-18
Patent
Electronic Resource
Japanese
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