Hodnocení kvality řeči v IP sítích

Abstract

This bachelor thesis deals with an evaluation of a speech quality in IP networks. The first part deals with speech quality overall and approaches to its evaluation using MOS scale.Next I followed up by the presentation of an E-model as one of the elements of the evaluation and R-factor which is used to evaluate according to ITU-T G.107. The most important is the practical part and the experiment under the influence of packet loss and delay in IP networks to MOS for different language mutations. There the experimental measuring workplace was used, where the measurement of speech samples was completed in Czech and English. This measurement was evaluated by using PESQ intrusive method and compared with the E-Model. After comparison,there was also made the correction of the E-model calculation using a regression analysis. Quite speech parameter was included as one of the factors influencing the evaluation. The comparison of measured and calculated results was carried out with MATLAB software.The output is the number of tools for the evaluation quality of speech and the language parameter supplementation into the calculation of the E-model.The results and achieved goals are evaluated at the end of my work.