Session Title:	Coding Efficiency
Session Chair:	Marina Bosi, AES Western Region VP, San Francisco, California, USA
Panelists:	Bernd Edler, University of Hannover, Hannover, Germany, Takehiro Moriya, NTT Human Interface Labs, Tokyo, Japan
Bernd Edler: Audio coding at very low bit rates requires very efficient evaluation of characteristics of the signal sources and of perpetual properties of the human ear. An overview of models for the signal source employed in different coding schemes is given. Some of the basic concepts for the perpetual quantization and coding of model parameters are shown, including approaches for scaleability with respect to bit rate and quality. Takehiro Moriya: In Internet application, good audio quality at low data rates (8-16kbit/s) audio coding is very valuable. While the ITU-T G.729 standard at 8 kbit/s provides toll quality for speech, quality for music signals is insufficient. TwinVQ (transform-domain Weighted Interleave Vector Quantization) is a transform coder based on LPC and vector quantization, and is capable of operating at kbit/s. The two approaches are compared from the view point of the fundamental technology, quality, delay and complexity.

Biographies:

Marina Bosi, Bernd Edler, Takehiro Moriya

Marina Bosi MARINA BOSI graduated from the National Conservatory of Music in Florence Italy and received a doctorate in physics from the University of Florence, completing her thesis in Paris at the Institut de Recherche et Coordination Acoustique/Musique (IRCAM). During her postdoctoral, Dr. Bosi carried out research in sound localization at Stanford University's Center for Computer Research in Music and Acoustics (CCRMA) where she is still a staff member. Dr. Bosi worked for Digidesign developing audio digital signal processing (DSP) technology including dynamic range controller and music analysis/synthesis algorithms. Dr. Bosi is involved with the development of international standards on low bit rate audio coding and is member of ANSI and a US representative in the ISO/IEC WG11 (MPEG), and ITU-R (formerly CCIR) standardization committees. The author of a number of publications on source coding for transmission and storage, her current area of interest is low bit rate coding with applications in music. Dr. Bosi has served the AES San Francisco Section as committee person, vice-chair, and chair. She served as a member of the AES Board of Governors and is currently vice president of the Western Region, USA/Canada. She was co-chair of the 97th AES Convention, for which she received the AES Board of Governors Award, and papers chair of the 101st AES Convention. Dr. Bosi is a member of the technical committee on Audio and Electroacoustics of the IEEE Signal Processing Society and a member of the Acoustical Society of America (ASA). Bernd Edler BERND EDLER received the Diplom (M.S. degree) in Electrical Engineering from the University of Erlangen, Germany in 1985. From 1986 to 1993 he was research assistant at the 'Institut fuer Theoretische Nachrichtentechnik und Informationsverarbeitung' of the University of Hannover, Germany. His main research areas were filter banks and transforms for source coding and he contributed to the development of the filter bank used in the MPEG-1 Layer 3 audio coder. Since 1993 he is staff member of the Systems Technology department at the 'Laboratorium fuer Informationstechnologie' which is a research institution of the University of Hannover. He received the Ph.D. degree in July 1994. His current work focuses on very low bit rate audio coding based on parametric signal representations for MPEG-4. Takehiro Moriya TAKEHIRO MORIYA received B.S. M.S. Ph.D degrees in 1978, 1980, 1989 all from University of Tokyo. In 1980 joined NTT research labs and has been involved in the research for low to medium speech and audio coding. In 1989 he stayed at ATT Bell Labs as an exchange researcher. Now he is a Distinguished Technical Member at NTT Human Interface Labs.

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