Containing 34 chapters, loosely grouped into six topical areas, this volume reflects the progress and presents the state of the art in low-bit-speech coding, primarily at bit rates from 2.4 kbit/s to 16 kbit/s. Together they represent important contributions from leading researchers in the speech coding community. The book contains contributions describing technologies that are under consideration as standards for such applications as digital cellular communications (the half-rate American and European coding standards). A brief introduction is followed by a section dedicated to low-delay speech coding, a research direction which emerged as a result of the CCITT requirement for a universal low-delay 16 kbit/s speech coding technology and now continues with the objective of achieving top quality with moderate delay at a rate of 8 kbit/s. A section on speech quality evaluation is then presented. This is followed by a section on speech coding for wireless transmission, and a section on audio coding which covers not only 7 kHz bandwidth speech, but also wideband coding applicable to high fidelity music.The book concludes with a section on speech coding for noisy transmission channels, followed by a section addressing future research directions. This volume also presents a cross-section of the key contributions in speech and audio coding which have emerged recently. For this reason, the book should be a valuable reference for all researchers and graduate students in the speech coding community.
