ECHO CANCELLATION DEVICE, ECHO CANCELLATION PROGRAM AND ECHO CANCELLATION METHOD

• Main Author: NAGAI TOSHIAKI
• Format: Patent
• Language: English; Japanese
• Published: 12.05.2016
• Subjects: DEAF-AID SETS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; PUBLIC ADDRESS SYSTEMS; TELEPHONIC COMMUNICATION; TRANSMISSION

PROBLEM TO BE SOLVED: To solve the problem that a conventional echo cancellation device cannot sufficiently attenuate an echo signal.SOLUTION: An echo cancellation device of the present invention is configured to output a first audio signal in which a frequency component in or higher than a target frequency is suppressed, and acquire an acoustic signal S2 including a frequency component higher than the target frequency. The echo cancellation device includes: an echo signal reduction processing part 18 for generating a transmission signal in which an echo signal component is reduced, from the acoustic signal S2; and a filter coefficient update discrimination part 17 for instructing the echo signal reduction processing part to update a filter coefficient when an echo signal component is included in an audio interval and in the acoustic signal S2 for an output audio signal S1. The filter coefficient update discrimination part 17 calculates a feature amount of the acoustic signal S2 and instructs the update of the filter coefficient when a difference between a first feature amount in a frequency band equal to or lower than the target frequency and a second feature amount in a frequency band higher than the target frequency is equal to or more than a preset update discrimination threshold.SELECTED DRAWING: Figure 3 【課題】従来のエコーキャンセル装置は、十分にエコー信号を減衰させることができない問題があった。【解決手段】本発明のエコーキャンセル装置は、ターゲット周波数以上の周波数成分が抑圧された第１の音声信号を出力し、ターゲット周波数よりも高い周波数成分を含む音響信号Ｓ２を取得する装置であって、音響信号Ｓ２からエコー信号成分を低減した送話信号を生成するエコー信号低減処理部１８と、出力音声信号Ｓ１が音声区間かつ音響信号Ｓ２にエコー信号成分が含まれる場合にエコー信号低減処理部にフィルタ係数の更新を指示するフィルタ係数更新判断部１７と、を有し、フィルタ係数更新判断部１７は、音響信号Ｓ２の特徴量を算出し、ターゲット周波数以下の周波数帯の第１の特徴量と、ターゲット周波数よりも高い周波数帯の第２の特徴量と、の差が予め設定した更新判断閾値以上であった場合に、フィルタ係数の更新を指示する。【選択図】図３