Wavelet based Noise Reduction Techniques for Real Time Speech Enhancement

Fixed noise suppression techniques are generally used for speech enhancement in different low power real time systems. In this paper, we propose a modified adaptive system for classification of speech signals and noise reduction based on multi-band techniques. It involves initial identification of incoming speech segments as clean speech, speech in noise or pure noise. For the noisy speech segments, background noise classification is carried out using different wavelet-based feature sets. Noise Reduction system consists of removal of adaptive stationary noise and non-stationary noise based on classified noise type. Simulation results show that the proposed system provides optimal noise reduction and better speech quality with reduced computational complexity in adverse noisy environments.