PROBLEM TO BE SOLVED: To provide a booming noise reduction device capable of sufficiently reducing a booming noise in the external auditory meatus which is uncomfortable for a user while preventing oscillation which becomes a problem in the case of performing negative feedback by using a microphone for the external auditory meatus.SOLUTION: A booming noise reduction device includes: a receiver 4 a microphone 5 for the external auditory meatus negative feedback circuits 40 and 41 and a signal bypass part 42. A signal Sout is converted into a sound by the receiver 4, and output to the inside of the external auditory meatus, and the sound and a booming noise are both converted into an electric signal by the microphone 5 for the external auditory meatus, and output to a negative feedback path. On the negative feedback path, predetermined frequency components are subjected to negative feedback via a low-band inverting amplification part 40 to a transmission path. A signal bypass part 42 functions as a bypass path from the input side of the receiver 4 to the output side of the microphone 5 for the external auditory meatus, and signal components whose phase change is small are transmitted via the signal bypass path 42. Thus, it is possible to sufficiently reduce the frequency components of the booming noise while preventing oscillation in a predetermined frequency.COPYRIGHT: (C)2015,JPO&INPIT【課題】外耳道用マイクロホンを用いて負帰還を行う際に問題となる発振を防止しつつ、使用者にとって不快な外耳道内のこもり音を十分に低減し得るこもり音低減装置等を提供する。【解決手段】本発明のこもり音低減装置は、レシーバ4と、外耳道用マイクロホン5と、負帰還回路40、41と、信号バイパス部42とを備えて構成される。信号Soutはレシーバ4で音に変換されて外耳道内に出力され、その音は、こもり音とともに、外耳道用マイクロホン5で電気信号に変換されて負帰還経路に出力される。負帰還経路では低域反転増幅部40を介して所定の周波数成分が伝送経路に負帰還される。信号バイパス部42はレシーバ4の入力側から外耳道用マイクロホン5の出力側までのバイパス経路として機能し、位相変化が少ない信号成分を信号バイパス部42を介して伝送し、所定の周波数における発振を防止しつつ、こもり音の周波数成分を十分に低減可能となる。【選択図】図2
