Research Of Objective Speech Quality Assessment Based On P.863

With the development of communication technology and application of multimedia products,multimedia service providers need a way to evaluate the quality of multimedia services in order to provide better service.Speech signal is the core of multimedia service,and the evaluation method of speech quality has become a hot research topic.Speech quality assessment is divided into subjective evaluation and objective evaluation.Subjective evaluation is high reliable,but time-consuming and laborious,and objective evaluation is convenient to take operation,but it is not reliable.In 2011,International Telecommunication Union proposed the new double end speech quality objective evaluation algorithm,ITU-T P.863.Compared to the previous doubleend algorithm,P.863 algorithm is applied more widely,but it still exist some problems with listener echo,short speech,etc..As a result,the accuracy of P.863 is not enough.For these problems,the paper analyzes the reasons of the emergence of P.863,combined with the method of echo parameter extraction,dynamic time warping,etc.,and puts forward an enhanced P.863 algorithm.It also develops a software system ofspeech quality objective evaluationbased on enhanced P.863 algorithm.The specific work of this paper is as follows:(1)In view of the P.863 algorithm,it is not accurate with processinglistener echo signal.Combined with many methods of echo detection,a method of listener echo detection and echo parameter evaluation is proposed.The error rate of the echo signal detected is reduced to 3%.(2)Based on listener echo detection method and MARS(multivariate adaptive regression spline),an enhanced P.863 algorithm is proposed,which improves the accuracy of the objective evaluation of speech quality.(3)Research reasons of inaccurateevaluation of short speechin P.863 algorithm,it optimizes time alignment steps of the algorithm,and improvesapplication scope of P.863.The evaluation correlation of short speech upgrades from 0.118 to 0.424.(4)A software system is developed based on the enhanced P.863's speech quality objective evaluation algorithm,which can evaluate the transmission speech signal.In browser,it provides the display and management with the speech signal.