Acknowledgments
The authors would like to thank Jürgen Koller from Fraunhofer Institut Integrierte Schaltungen for the support while writing this paper as well as Dr. Kazunori Ozawa, Dr. Masahiro Serizawa, and Mr. Toshiyuki Nomura of C&C Media Research Laboratories, NEC Corporation, for their valuable comments and discussions. Thanks to Bodo Teichmann and Bernhard Grill for supplying figures. Part of the work at Fraunhofer IIS was supported by the European Commission (ACTS MoMuSys) and the Bavarian Ministry for Economy, Transportation and Technology. MPEG-4 natural audio is the joint effort of numerous people who worked hard to make the vision of a exible multimedia coding system a reality. We want to mention the work of Peter Schreiner, the chair of the audio subgroup in MPEG, and David Meares, the audio secretary, and all the others who worked together to create MPEG-4 audio.