Abstract: In this high-tech environment, the use of digital communication systems like hands-free systems for delivering speech in the classroom or in an auditorium are becoming more popular. In such situations, the loudspeaker and a high-gain microphone are commonly found. But, the presence of a large acoustic coupling between loudspeaker and the microphone would produce a loud echo and the background noise that reduces the quality of speech and results in inconvenience to the listeners. The solution to these problems is the elimination of the echo using an echo cancellation algorithm. The basic component of an echo canceller is an adaptive filter which creates a replica of the echo and subtracts it from the combination of the actual echo and the near-end signal. In this paper, the speech signal in an auditorium environment has been enhanced by eliminating the echo and noise signal by adopting an adaptive filter algorithm called Average RLS and using Band pass filter in pre-processing step. Finally for evaluating the performance of the algorithm, the parameters such as Mean Square Error (MSE) and ERLE (Error rate loss enhancement) are measured.

Keywords: Echo-Cancellation algorithm, Adaptive filters algorithm, Average RLS, Mean Square Error (MSE) and ERLE (Error rate loss enhancement).