Personal reflections on research in speech coding: From LPC to CELP
Hosted by: Professor Fan-Gang Zeng
*Personal Reflections on Research in Speech Coding: From LPC (linear predictive coding) to CELP (code-excited linear prediction)*
*Speaker:* Bishnu S. Atal, University of Washington, Seattle, Department of Electrical Engineering
*Time:* Noon *Date:* Thursday, May 24
*Location:* Calit2 Auditorium
*Abstract:* Research in speech coding originated about 75 years ago. It all started with the desire to transmit voice signals over undersea telegraph cables. Atal joined Bell Labs, Murray Hill in 1961 and started his research in speech coding (compression) in 1966, before there were good applications in sight. In his talk, he will share personal impressions of this research as he navigated his way, from basic LPC to multi-pulse and to code-excited linear prediction (CELP). The semiconductor revolution produced faster and faster DSP chips and made CELP practical. Speech coding technology is widely used now in many applications, such as digital cellular phones, personal computers and VoIP.
*Bio:* Bishnu S. Atal is an affiliate professor in the Department of Electrical Engineering at the University of Washington, Seattle, WA. He retired in March 2002 after working for more than 40 years at Lucent Bell Labs and AT&T Labs. He was a technical director at the AT&T Shannon Laboratory, Florham Park, New Jersey, where he was engaged in research in speech coding and in automatic speech recognition. Previously, he was the head of the Acoustics and Audio Communication Research Department at Bell Laboratories, Murray Hill, N.J. He was named a Bell Laboratories Fellow in 1994 and an AT&T Fellow in 1997.
Atal received the B.Sc. (Honors) degree in physics from the University of Lucknow (India) in 1952, the diploma in electrical communication engineering from the Indian Institute of Science, Bangalore (India) in 1955, and a doctorate degree in electrical engineering from the Polytechnic Institute of Brooklyn, New York, in 1968. He joined the technical staff of AT&T Bell Laboratories in 1961, became head of the Acoustics Research Department in 1985, and head of the Speech Research Department in 1990.
His research work centered in the fields of acoustics and speech processing covering a wide range of topics, such as computer simulation of concert halls, fading in mobile radio, automatic speaker recognition, and low bit rate speech coding. He is internationally recognized for his contributions to speech analysis, synthesis and coding. His pioneering work in linear predictive coding of speech established linear prediction as one of the most important speech analysis techniques, leading to many applications in coding, recognition and synthesis of speech.
Atal invented multi-pulse linear predictive coding and code-excited linear prediction (CELP) which have found widespread applications in efficient transmission of speech in telephone networks. The CELP voice coders have been adopted as standards for digital transmission of voice on cellular radio systems in North America, Europe, Japan and elsewhere in the world to meet the increasing demand for cellular phones. His current research interests include low bit rate speech coding and automatic speech recognition. His research work is documented in more than 90 technical papers and he holds 17 U.S. and numerous international patents in speech processing.
He was elected to the National Academy of Engineering in 1987 and to the National Academy of Sciences in 1993. He is a Fellow of the Acoustical Society of America and the IEEE. He received the IEEE Signal Processing Society Award in1993 for contributions to linear prediction of speech, multi-pulse and code-excited source coding, and the 1975 IEEE ASSP Society Technical Achievement Award for fundamental contributions to linear predictive coding of speech signals. In 1980 he received, jointly with M. R. Schroeder, the IEEE ASSP Senior Award. He is the recipient of the IEEE Centennial Medal in 1984 and the IEEE Morris N. Liebmann Memorial Field Award in 1986 for his pioneering contributions to linear predictive coding for speech processing. He received the Thomas Edison Patent Award from the R&D Council of New Jersey in 1994, and the New Jersey Inventors Hall of Fame ?Inventor of the Year Award? in 2000. He was awarded the Benjamin Franklin Medal in Electrical Engineering in 2003. Other recipients of this prestigious award include Alexander Graham Bell, Guglielmo Marconi, and John Pierce. He has co-edited two books, "Advances in Speech Coding" and ?Speech and Audio Coding for Wireless Network Applications," with V. Cuperman and A. Gersho.