Title :
A new variable rate speech coder based on fuzzy phonetic classification and CS-ACELP structure
Author_Institution :
Istituto di Inf. e Telecommun., Catania Univ., Italy
Abstract :
This paper presents a new variable bit-rate CELP speech coder based on fuzzy phonetic classification and CS-ACELP structure. The codec exploits new robust algorithms of multilevel phonetic classification and efficient activity/inactivity speech coding models. It uses 8 operating modes ranging from 0 to 8 kbit/s with an average bit rate of 4 kbit/s and an algorithmic delay of 15 ms. Subjective listening tests, performed in several acoustic noise conditions, demonstrate that performance is better than that of the GSM full-rate codec at 13 kbit/s and similar to that of the latest ITU-T standard for speech coding at 8 kbit/s, both in the discontinuous transmission mode
Keywords :
acoustic noise; fuzzy logic; linear predictive coding; signal classification; speech coding; speech processing; variable rate codes; vocoders; 0 to 8 kbit/s; 13 kbit/s; CS-ACELP structure; acoustic noise; activity/inactivity models; discontinuous transmission mode; fuzzy phonetic classification; performance; subjective listening tests; variable rate speech coder; Acoustic noise; Acoustic testing; Bit rate; Code standards; Codecs; Delay; GSM; Performance evaluation; Robustness; Speech coding;
Conference_Titel :
Signal Processing Proceedings, 1998. ICSP '98. 1998 Fourth International Conference on
Conference_Location :
Beijing
Print_ISBN :
0-7803-4325-5
DOI :
10.1109/ICOSP.1998.770280
