The noise existence is inevitable in real applications of speech processing. It is well known that the additive noise affects negatively the performance of the speech codecs designed to work with noise-free speech especially codecs based on linear prediction coefficients (LPC). Another application strongly influenced by noise is related to the hands free phones where the background noise reduces the signal to noise ratio (S/N) and the speech intelligibility. The classical systems for noise suppression rely on the usage of adaptive linear filtering and the application of digital filters with finite impulse response (FIR). The strong points of this approach are the simple analysis of the linear systems in the process of adaptation and the guaranteed stability of FIR structures.