This book splits the difference between a purely academic and a practical approach. It does talk a great deal about the history of various audio representations, and it has some derivations, but it also has some practical numerical examples inserted into the narrative that help explain some of the audio concepts. The exercises at the end of each chapter are on the practical side, stressing numerical problems and MATLAB computer exercises over pure derivations.

The book spends the first six chapters going over the basics that you need to know to understand or implement audio coding schemes. Chapter two reviews basic signal processing concepts associated with audio coding. Chapter 3 provides introductory material to waveform quantization and entropy coding schemes. Some of the key topics covered in that chapter include scalar quantization, uniform and nonuniform quantization, pulse code modulation, differential PCM, adaptive DPCM, vector quantization, bit allocation schemes, and entropy coding techniques such as Huffman, Rice, and arithmetic methods. Chapter 4 provides information on linear prediction and its application in narrow and wideband coding. In chapter 5, where psychoacoustic principles are described, Johnston's notion of perceptual entropy is presented as a measure of the fundamental limit of transparent compression for audio. Chapter 6, on filter bank design issues and algorithms, places particular emphasis on the modified discrete cosine transform which is widely used in several perceptual audio coding algorithms. The chapter also addresses pre-echo artifacts and control strategies.

Chapters 7,8, and 9 review established and emerging techniques for transparent coding of FM and CD-quality audio signals, including several algorithms that have become international standards. Transform coding methodologies are described in chapter 7, subband algorithms are discussed in chapter 8, and sinusoidal algorithms are presented in chapter 9.

Chapter 10 discusses the standardization activities in audio coding. It describes coding standards and products such as the ISO/IEC MPEG family. Details on popular standards, such as the MP3 and MPEG-4 AAC algorithms, are provided. Chapter 11 focuses on lossless audio coding and digital audio watermarking techniques. In particular, the SHORTEN, the DVD algorithm, the MUSICompress, the AudioPaK, and other such coding schemes are described in detail. Chapter 12 provides information on subjective quality measures for perceptual codecs. The five-point absolute and differential subjective quality scales are addressed. A set of subjective benchmarks is provided for the various standards in both stereophonicand multichannel modes so that algorithms can be more easily compared.

If you've never been exposed to the subjects discussed in chapters one through six, you'll find this book rough going, since there are entire books written on the subjects that this book is covering in just one chapter each. However, I think it is a good review and a good way for those that are accustomed to looking at these problems from a purely mathematical perspective to see them from the viewpoint of audio processing and coding and to see problems solved using MATLAB. Chapters 7 through 9 are very good at presenting the various algorithms and illustrating them, but the quality seems to drop off as far as details go in the final three chapters starting with the sections on the MPEG standards in chapter 10. This book is good for background and reference, but don't expect to be able to decode or encode anything based solely on what's presented here.