First off, this book is in its fifth edition, and Amazon has lumped together reviews of all editions of this book. So the oldest review shown, written in 1998, is speaking of the 3rd edition, and reviews written prior to 2005 are talking about the 4th edition.
This book is more about the principles of digital audio hardware design than anything. The author, also a college professor, starts with the absolute beginning and the binary number system, sampling, quantization, aliasing, and dither and then moves into all of the topics that you need to design and analyze modern digital audio systems. However, if the information in the first two chapters is news to you, chances are the rest of the book will be over your head. The book is full of flow charts, frequency response diagrams, and detailed block diagrams of actual systems. What it is lacking in is any kind of signal processing mathematics to explain the detailed theory behind what is being covered. There is a chapter entitled "Digital Signal Processing", but it barely introduces and defines the terms. It does show some assembly code for performing some simple filtering tasks, though, but that's the extent of the coverage. If you didn't know DSP before you read this chapter, you certainly won't know it after you read this chapter. The book does a pretty good job of discussing some of the more popular audio standards including MP3. I think this book is best suited for someone with an electronics/electrical engineering background that already knows the theory of digital signal processing and wants to apply that knowledge to the actual design and analysis of digital audio processing systems. Amazon shows the table of contents from the 4th edition, so I show the detailed table of contents for the 5th edition here:
Sound and Numbers
Fundamental Theory
Digital Audio Recording
Digital Audio Reproduction
Error Correction
Digital Audio Tape
Optical Disc Storage
Compact Disc and SACD
Recordable CD
Interconnection
Perceptual Coding: Theory and Applications
MPEG-1 and MPEG-2
MP3 Codec
MPEG-4 and AAC
Psychoacoustic Models
Surround Sound Coding
Lossless Coding
DVD-Video and DVD-Audio
Recordable DVD
HD-DVD and Blu-ray
Minidisc
Desktop Audio
Network Audio
Downloadable and Streaming Internet Audio
File Formats
Digital Rights Management
Watermarking and Encryption
MPEG-7
Digital Radio and TV Broadcasting
HD Radio
Satellite Radio
Digital Audio Workstations
Digital Signal Processing: Theory and Applications
Sigma Delta Conversion and Noise Shaping