Firstly it reviews and compares the two major ways to achieve echo cancellation, which are the acoustic echo canceller (AEC)and acoustic echo suppressor (AES) in frequency domain.

• 首先我们对两种主要方式在实现回声消除技术中进行了研究和比较，它们是：回声波取消器 (AEC) 和声学回声的 (AES)抑制器频域。