Influence of Russian, Spanish and Vietnamese speech characteristics on digital information quality

This work deals with the problems of modeling of probabilistic characteristics of Russian, Spanish and Vietnamese speech information. It shows the influence of characteristics of speech information on the quality of transmission in digital systems, including Integrated Service Digital Network (ISDN). The main feature of digital transmission systems, including ISDN is digitization of permanent time signal with its further integration on the receiving side. During the examination of any transmission system of speech information it is necessary to estimate the quality of speech transmission, i.e., to estimate the error of interpolation of the initial signal. The subject of the research conducted by the authors is the process of transmission and interpolation of digitized voice signal; the purpose is the establishment of the mathematics and techniques of the analytical evaluation of the transmission quality. To fulfil this task it was necessary to examine the structure of the voice signal. The voice signal was considered as a quasi permanent random process and was described by such characteristics allowing the result of analysis of the system of speech transmission to be obtained with precision, which is sufficient for engineering