公开(公告)号：US5384843A

公开(公告)日：1995-01-24

申请号：US122787

申请日：1993-09-15

申请人： Hiroyuki Masuda ,  Kazutoshi Hosokawa ,  Kensaku Fujii ,  Juro Ohga

发明人： Hiroyuki Masuda ,  Kazutoshi Hosokawa ,  Kensaku Fujii ,  Juro Ohga

IPC分类号： H04B3/23 ,  H04M1/60 ,  H04M9/08

CPC分类号： H04B3/23 ,  H04M9/082

摘要： An acoustic echo canceler and a side-tone echo canceler provided in a hands-free telephone suppress an acoustic echo and a side-tone echo respectively with few error by providing automatic gain controllers and/or limiters in the hands-free telephone so that the acoustic echo canceler and the side-tone echo canceler operate in linear, and a directional characteristic of a microphone used in the hands-free telephone for reducing the acoustic echo is controlled by a microphone direction controller so that the microphone operates as an omnidirectional microphone when a level of a received signal of the hands-free telephone is less than a designated level and as a bidirectional microphone when the level exceeds the designated level, further gains of an output of the microphone increases in a low frequency range.

摘要翻译： 在免提电话机中提供的声学回波消除器和侧音回波消除器通过在免提电话中提供自动增益控制器和/或限制器来分别抑制声回声和侧音回波，具有很少的误差，使得 声回波消除器和侧音回波消除器以线性方式工作，并且用于减少声回波的免提电话中使用的麦克风的方向特性由麦克风方向控制器控制，使得话筒作为全向麦克风操作，当 当电平超过指定电平时，免提电话的接收信号的电平小于指定电平，并且作为双向麦克风，麦克风的输出的进一步增益在低频范围内增加。