Digital Audio Fundamentals
John Watkinson14.1 Audio as Data ........................................................................................................
The most exciting aspects of digital technology are the tremendous possibilities that were
not available with analog technology. Many processes that are diffi cult or impossible
in the analog domain are straightforward in the digital domain. Once audio is in the
digital domain, it becomes data, and only differs from generic data in that it needs to be
reproduced with a certain time base.
The worlds of digital audio, digital video, communication, and computation are closely
related, and that is where the real potential lies. The time when audio was a specialist subject
that could evolve in isolation from other disciplines has gone. Audio has now become a
branch of information technology (IT); a fact that is refl ected in the approach of this book.
Systems and techniques developed in other industries for other purposes can be used to
store, process, and transmit audio, video, or both at once. IT equipment is available at low
cost because the volume of production is far greater than that of professional audiovisual
equipment. Disk drives and memories developed for computers can be put to use in
such products. Communications networks developed to handle data can happily carry
audiovisual data over indefi nite distances without quality loss.
As the power of processors increases, it becomes possible to perform under software
control processes that previously required dedicated hardware. This allows a dramatic
reduction in hardware cost. Inevitably the very nature of audiovisual equipment and the
ways in which it is used is changing along with the manufacturers who supply it. The
computer industry is competing with traditional manufacturers, using the economics of
mass production.
CHAPTER 14