Systematic integration of acoustic echo canceller and noise reduction modules for voice communication systems

This paper proposes an efficient way of integrating acoustic echo canceller (AEC) and background noise reduction (NR) modules for voice communication systems. The main strategy for designing a standalone AEC or NR module is straightfor- ward, but it is not easy to integrate two modules in a single system because of the undesired effect caused by the nonlinear nature of each module's output. The proposed algorithm di- rectly estimates noise and echo components from the observed signal, then they are utilized in the process of updating AEC module. Since the estimation step is independent of the ac- tual processing of NR module, the nonlinear effect caused by coupling the NR module with the AEC module can be mini- mized. Experimental results show that the proposed algorithm achieves the performance of standalone AEC in terms of echo- return-loss-enhancement (ERLE) metric while maintaining that of standalone NR module in the spectral distortion aspect.