Feedback Cancellation in Speech Signal using LMS Algorithm

Abstract

Acoustic feedback is a well-known problem in reinforcement systems, which is caused by the undesired acoustic coupling between the loudspeaker and the microphone. Acoustic feedback limits the maximum amplification used in the reinforcement systems without making it unstable. Feed forward suppression techniques are widely used in this context to alternate the forward path in the reinforcement systems and reduce the feedback signal. However, they limit the amplification in the forward path and can lead to severe sound quality distortions in loudspeaker signal.
This paper focuses on the adoption of the Least Mean Square (LMS) Algorithm of adaptive filtering as a solution to reduce this unwanted signal in speech signal and thus increase speech quality. LMS algorithm of adaptive filtering in the cancellation system is then validated by computing the filter coefficients using discrete signal processing in MATLAB. Dr. Bassam Lala