Development and analysis of distributed acoustic echo cancellation microphone system

Abstract

Abstract Acoustic echo cancellation using an adaptive transversal filter and the least mean square algorithm is the most effective technique of reducing acoustic echoes in a hands-free telephone system. However, a very high-order adaptive filter and multiple echo paths for each microphone result in difficulties in algorithm convergence and hardware implementation. This paper presents a distributed system which performs acoustic echo cancellation in the microphone unit. Each acoustic echo cancellation microphone unit has two closely spaced directional microphones pointing in opposite directions and a much lower order adaptive filter than in the earlier systems. Computer simulations were conducted based on real speech data collected from a typical conference room. Finally, a robust double-talk detector, which identifies three modes of operation, was developed and tested in real-time