Comparison of MFCC and PLP Parameterizations in the Speaker Independent Continuous Speech Recognition Task

摘要

The authors of this paper wish to contribute to the discussion about an optimal parameterization of speech signals in speech recognition systems. Our experiments deal with a telephone-based speaker independent continuous speech recognition task in which the MFCC and PLP parameteriza-tions were tested and compared. The benefit of an adjustment of the filters used in the MFCC and PLP parameterizations to the critical bandwidth of hearing was explored and the impact of the number of filters and enumerated parameters to the recognition accuracy was tested. The results of these experiments showed that the MFCC parameterization is less sensitive to satisfying the theory of the critical bandwidth of hearing than the PLP parameterization. Experiments also proved that 5 PLP-cepstral (including derived 5 delta + 5 delta-delta) coefficients do not afford the best results as could be deduced from recent work. However, after optimal setting both parameterization techniques provided almost comparable results.