INFLUENCE OF LANGUAGES ON CELP CODECS PERFORMANCE

Abstract

This paper investigates the performance of speech codec's that uses linear predictive coding (LPC), over different languages. Investigations show that most low-rate (8kbits/s and below) speech coders show bias towards non-accented English. When the coders are used for heavily accented English or other languages, significant performance degradation is noted. In order to judge the performance of the most popular speech codec’s (Speex and AMR), we encoded and decoded the speech samples from three different languages: English, Arabic and Lithuanian. The quality of transformed speech signals was estimated using two quality estimation techniques 3SQM and PESQ algorithms according to ITU recommendations P.563 and P.862. The results showed quality bias toward the English language – the scores were hgiher and the performance was more stable.