电话会议系统的合成立体声和声学回波消除

从理论上分析和比较了不同应用场合的电话会议系统中单通路传输音频信号立体声化的几种方法．利用简化的头相关传输函数对单音频信号进行处理，使之扩展为两路立体声信号，同时指出了这种方法存在的局限性和需改进的方面．另外，在论述自适应的多路回波消除问题和原因后，分析和比较了现有的几种消除结构，指出采用每空间一个滤波器的合成立体声回波消除结构，通过将合成主体声的方式与设置滤波器结合起来是今后发展的一个主要方向．

Synthesized Stereo and Acoustic Echo Cancellation in Desktop Conference System

Taking into consideration of the different situations in which the des ktop conference system was applied, several solutions to the synthesis of stereo signals from mono acoustic signals were theoretically analyzed and compared, wi th emphasis on the processing method of the simplified head related transfer fun ction. In this method, mono acoustic signals were processed and extended to ster eo signals. The limitation and the aspects to be improved of the proposed method were also indicated. Moreover, by discussing the self-adaptive acoustic echo ca ncellation and its causes, several existing echo cancellation structures were an alyzed and compared. It is indicated that the structure with a single filter per spatial region is a promising direction of research in echo cancellation, in wh ich synthesizing stereo signal and setting filter are perfectly combined.