One period of research of advanced multimedia transmission has been finished in our department. A lot of papers from this problem were published in the previous conferences and this paper encloses it. The main problems were mapping the actual status of audio signal encoding and bit rate compression, focused to MPEG-1 method, encoder and decoder MPEG-1 block diagrams and design of MPEG-1 model simulated by MATLAB. This model was suitable for testing and optimizing of MPEG-1 principle, analysis and simulation of the Filter Bank, design and modification of scale-factor calculating, modelling of FFT for MPEG-1, determination of the sound pressure level, study of tonal and non- tonal components, decimation of tonal and non-tonal masking components design, individual masking threshold and global masking threshold, determining the minimum masking threshold, signal-to-mask ratio, design of bit allocation and optimal quantisation and encoding of subbands samples.