Influence of multiple GSM coding and decoding on MFCC

This article presents the results of studies on the effects of multiple transcoding operations in the case of GSM standards. Differences between the MFCC coefficients, obtained by successive transcoding were considered. The aim of comparisons is to check the possibility for separation and detection of the used GSM encoder. During the research we used the TIMIT database recordings, transcoded four times by the GSM codecs. A possibility of separation was analyzed between the curvilinear approximations of the MFCC coefficients errors.