android系统通话中回声消除的实现

为了消除android系统电话免提通话时产生的声学回声,利用静音检测（VAD）机制,在android系统开源代码软件asterisk模块中,加入声学回声消除算法。通过不断比较来话音和去话音数据,判断是否为声学回声并进行白噪声替换,测试结果表明在一般的通话环境中,可以消除正常语音通话时90%以上的回声,实现半双工通信,适合于嵌入式android终端设备的开发。

Acoustic Echo Cancellation in android calls

In order to eliminate the acoustic echo in the android system for hand-free calls,an acoustic echo cancellation algorithm,with voice activity detection(VAD) mechanism,is added to the module of android system.Through the continuous comparison with the voice data,the acoustic echo is determined and the white noise replaced.The experimental results indicate that,in a normal voice call,90% of the echo could be eliminated,thu the half duplex communication realized,and this is applicable to the development of emb...