“…Some noise reduction techniques are based on digital filters, wavelet transform and adaptive filtering (AlMahamdy and Riley, 2014); singular value decomposition (Bandarabadi and Karami-Mollaei, 2010); independent component analysis (Phegade and Mukherji, 2013) and S-transform (Das and Ari, 2013). Among the algorithms for PLI removal there are digital processing methods based on: fuzzy thresholding (Üstündağ et al, 2012); nonlinear filter bank (Łęski and Henzel, 2005); Fast Fourier Transform and adaptive nonlinear noise estimator (Shirbani and Setarehdan, 2013); Empirical Mode Decomposition (Agrawal and Gupta, 2013); neural networks (Mateo et al, 2008) and wavelet transform (Agrawal and Gupta, 2013;Garg et al, 2011;Poornachandra and Kumaravel, 2008;Rahman et al, 2010).…”