63 Real-Time Noise Canceller Using Modified Sigmoid Function RLS Algorithm V.K. Gupta, D.K. Gupta and Mahesh Chandra © Springer India 2015 I.K. Sethi (ed.), Computational Vision and Robotics, Advances in Intelligent Systems and Computing 332, DOI 10.1007/978-81-322-2196-8_8 Abstract In this paper, modified sigmoid function RLS (MSRLS) algorithm is proposed for online noise cancellation from audio signals. The experiments are performed using TMS320C6713 processor with code composer studio (CCS) v3.1. The performance of RLS and MSRLS algorithms is evaluated and compared for noisy signals with car noise, F16 noise, and babble noise at -5, 0, and 5 dB SNR levels. The proposed MSRLS algorithm has shown a maximum of 2.03 dB improvement in SNR over RLS algorithm at input signal of -5 dB SNR with F16 noise. The proposed MSRLS algorithm has also shown decrement in mean square error (MSE) at all SNR levels for all noises in comparison with RLS algorithm. Keywords Adaptive filter · RLS · MSRLS · TMS320C6713 · SNR · MSE 1 Introduction The problem of controlling the noise level in the environment has been the focus of a tremendous amount of research over the years. In the process of transmission of information with a microphone, through a channel, noise automatically gets embedded to the signal which affects the quality of the audio signal. The objec- tive is noise minimization and quality improvement of the signal through hardware V.K. Gupta (*) Department of ECE, Inderprastha Engineering College, Ghaziabad, India e-mail: guptavk76@gmail.com D.K. Gupta Department of ECE, Krishna Engineering College, Ghaziabad, India e-mail: deepak_gpt@rediffmail.com M. Chandra Department of ECE, Birla Institute of Technology, Mesra, Ranchi 835215, India e-mail: shrotriya69@rediffmail.com