Research On Chinese Speech Quality Measure Based On Mel Cepstrum And Bark Spectrum Distortion Distance

The speech quality measure has been used in every field of speech investigation and aroused great attention among research, design and production of speech transportation system. Every speech transportation system or network must be measured before programming, exploiting, producing, etc. An effective measure way can test not only the speech coder but also the channel of communication. Neoteric way in speech quality measure is subjective measure mainly because it is assessed by human ear that the quality of speech can be finally evaluated. However, subjective measure can be done only under a certain circumstance. What' s more, it will be influenced since it is impossible for human to give the same measure at different time. It is because of this, objective measure for speech quality is required.First, the development of objective measure is introduced in the paper. Then, human pronunciation system and acoustical system are presented for the research of speech quality measure involves not only the knowledge of signal processing but also that of psychologic acoustics. As to the research of distortion estimate, Mel cepstrum distortion and Bark spectrum distortion are discussed in detail. And they are used to evaluate the speech quality objectively so that higher correlations between objective measure and subjective MOS are gained. Meanwhile, to the Chinese continuous sentence group, the definition of Complementary Masking Matrix is proposed. Using it to measure the speech, the correlation to MOS enhance from one to two percents. Considering the particularity of the number with Chinese pronunciation, Hamming window that is often used to cut speech signal short is replaced by rectangle window in the Mel cepstrum distortion measure. And few less than one percent is enhanced. Finally, the conclusion and the expectation about this project are presented.