Title :
High-quality coding of telephone speech and wideband audio
Author :
Jayant, Nikil S.
Author_Institution :
AT&T Bell Lab., Murray Hill, NJ, USA
Abstract :
Digital speech technology is reviewed, with the emphasis on applications demanding high-quality reproduction of the speech signal. Examples of such applications are network telephony, ISDN terminals for audio teleconferencing, and systems for the storage of audio signals, which include the important subclass of wideband speech. Depending on the application, the bandwidth of input speech can vary from about 3 kHz to nearly 20 kHz. Coding for digital telephony at 4 and 8 kb/s, network quality coding at 16 kb/s, and coding for audio at 7 and 20 kHz are examined. Future directions in the field are discussed with respect to anticipated technology applications and the algorithms needed to support these technologies.<>
Keywords :
ISDN; audio signals; encoding; reviews; speech analysis and processing; teleconferencing; telephony; 20 kHz; 4 kbit/s; 7 kHz; 8 kbit/s; ISDN terminals; audio signals; audio teleconferencing; digital speech technology; high-quality reproduction; review; speech coding; telephony; wideband audio; Bandwidth; Bit rate; GSM; Land mobile radio; Pulse modulation; Robustness; Speech coding; Telephony; Vocoders; Wideband;
Journal_Title :
Communications Magazine, IEEE
