Fundamentals of Digital Audio (review)

Alan Kefauver: Fundamentals of Digital Audio. Softcover, 1999, ISBN 0-89579-405-5, 174 pages, illustrated, glossary, bibliography, index; A-R Editions, Inc., 801 Deming Way, Madison, Wisconsin 53717-1903, USA; telephone (800) 736-0070 or (608) 836-9000; fax (608) 831-8200; electronic mail orders@areditions.com; World Wide Web www.areditions.com

Since I too, like the author, am a teacher, I tend to evaluate a book like Alan Kefauver's Fundamentals of Digital Audio, published by A-R Editions, for its potential as a college text. In that, Mr. Kefauver's book succeeds admirably. It is well organized, the elementary explanations are clear and succinct, and most of the charts and drawings are well rendered and illuminate the text.

The book begins with a chapter on the basics of sound and sound reproduction. More on that later. The balance of the book is organized similarly to the digital audio process itself. Chapter Two discusses all of the basics of analog to digital conversion, sampling theory, and quantization. This chapter well explains the Nyquist theorem and gives a clear account of the relationship of bit depth to signal-to-noise ratio. I was not entirely happy with the explanation of aliasing and the creation of false frequencies; the author could have easily included the computation of alias frequencies at different sampling rates. Mr. Kefauver goes to great pains throughout the book to avoid mathematical clarification or explanation. That he does this so admirably is a testament to his many years successfully teaching these concepts to aspiring recording engineers. Is it necessary or even desirable, though, to always bend over backwards to accomplish these highly technical topics with a minimum of math? I think not.

Chapter Three takes on the task of explaining how the digital information is reconstructed into an analog signal. Mr. Kefauver does an excellent job explaining digital-to-analog converters, error detection, oversampling, and one-bit conversion. While reading this chapter (and the next five), I had to constantly remind myself that this is an introductory text on digital audio for the student, not a comprehensive scholarly work targeted to computer scientists or electronics engineers.

Chapters Four and Five discuss storage systems. First, tape-based systems, then disc. Much effort is expended to explain the different formats currently in use for archiving and storage. Both optical and magnetic systems are discussed in detail. Special mention should be made concerning the author's comprehensive descriptions of the various flavors of compact disc (CD) and digital video disc (DVD). In my opinion, this is the most comprehensive section of the book and well worth the purchase price.

Chapters Six and Seven discuss applications and techniques of digital audio editing and workstation operations. Mr. Kefauver first gives us a brief historical overview of computer-based audio editing and then proceeds to discuss, in a very general way, the operation of software for editing and production. Since tying these chapters too closely to a specific system would probably limit the potential audience, his explanations are extremely generic and therefore limited. I'm not sure what he hoped to accomplish in these chapters except to offer the reader a very brief and general overview of the subject with few specifics.

Finally, Chapter Eight gives a short overview of digital audio transmission schemes. AES/EBU (Audio Engineering Society/European Broadcasting Union) and S/PDIF (Sony/Philips Digital Interface Format) are the dominant formats discussed, with a word or two about their history and usefulness. Not much more is said after pointing out the brief existence of a few proprietary formats which are now obsolete. Brief mention is made of digital transmission in radio.

The appendix includes a good glossary of terminology, an excellent bibliography, and an index.

In my opening paragraph I mentioned that I would tackle the issue of Chapter One later. My question: Why does each and every audio or electronic/computer music text seem to begin with an introductory chapter on sound including a little...