Developing technologies and how
these have shaped popular music
Digital audio refers to technology that records, stores, and reproduces
sound by encoding an audio signal in digital form instead of analogue form.
Introducing digital audio…
Digital audio systems may include compression, storage, processing and
transmission components. Conversion to a digital format allows convenient
manipulation, storage, transmission and retrieval of an audio signal.
Sony developed the first digital audio recording devices to be used by
professional studios in 1978. The next year, Sony revolutionized the world of
personal audio with the introduction of the Walkman portable audio
cassette player, initially called the “Soundabout.”
Though compact disc technology emerged the following year, Sony went on
to sell over 100 million Walkman-like audio players—and that was in addition
to innumerable knock-offs by other manufacturers, even before personal
audio players evolved to play digital mediums such as compact discs (1988)
and minidiscs (1992).
The first commercially available digital audio players in the United States
using the MP3 format (which had been in development since 1987) would
launch the digital audio player revolution that achieved meteoric success
with the introduction of Apple’s iPod in 2001 (Holmes 2006).
(DAT or R-DAT) is a signal recording and playback medium developed by Sony and
introduced in 1987. In appearance it is similar to a Compact Cassette, using 4 mm
magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm
54 mm 10.5 mm
Digital AudioTape (DAT)
DAT has the ability to record at higher, equal or lower
sampling rates than a CD (48, 44.1 or 32 kHz sampling
rate respectively) at 16 bits quantization. If a digital
source is copied then the DAT will produce an exact
clone, unlike other digital media such as Digital
Compact Cassette or non-Hi-MD MiniDisc, both of
which use a lossy data reduction system.
The technology of DAT is closely based on that of video recorders, using a rotating head and
helical scan to record data. This prevents DATs from being physically edited in the cut-and-
splice manner of analog tapes, or open-reel digital tapes like ProDigi or DASH.
Although intended as a replacement for audio cassettes,
the format was never widely adopted by consumers
because of issues of expense and concerns from the music
industry about unauthorized digital quality copies.The
format saw moderate success in professional markets and
as a computer storage medium.
More on DAT
Sony DCT-690 : DAT-Recorder
DigitalAudioTapeVs. Analogue Cassette
The compact disc, or CD for short, is an optical disc used to store digital data. The
format was originally developed to store and play back sound recordings only (CD-
DA), but was later adapted for storage of data (CD-ROM). Audio CDs and audio CD
players have been commercially available since October 1982.
Compact Disc (CD)
At the time of the technology's introduction it had more
capacity than computer hard drives common at the time.
The reverse is now true, with hard drives far exceeding
the capacity of CDs. The Compact Disc is an evolution of
LaserDisc technology. Prototypes were developed by
Philips and Sony independently from the mid-to-late
1970s.The two companies then collaborated to produce a
standard format and related player technology which was
made commercially available in 1982.
In 1974, an initiative was taken by L. Ottens, a director of the audio industry group
within the Philips Corporation in Eindhoven, the Netherlands. A seven-person
project group was formed to develop an optical audio disc with a diameter of 20 cm
with a sound quality superior to that of the large and fragile vinyl record. Later in
1979, Sony and Philips set up a joint task force of engineers to design a new digital
audio disc. First published in 1980, the standard was formally adopted by the IEC as
an international standard in 1987, with various amendments becoming part of the
standard in 1996.
How CDs are made
More on CD
A news report on the debut of the CD
DCC is a magnetic tape sound recording format introduced by Philips and Matsushita
in late 1992 and marketed as the successor to the standard analogue Compact
Cassette. DCC was envisaged as a cheaper alternative to DAT. DCC shared a similar
form factor to analogue cassettes, and DCC recorders could play back either type of
cassette. This backward compatibility allowed users to adopt digital recording
without rendering their existing tape collections obsolete.
Digital Compact Cassette (DCC)
DCC signalled the parting of ways of Philips and Sony,
who had worked together successfully on the Compact
Disc, CD-ROM and CD-i before. Based on the success of
Digital AudioTape in professional environments, both
companies saw a market for a new consumer-oriented
digital audio recording system that would be less
expensive and perhaps less fragile. DCC was developed in
cooperation with Matsushita, and the first DCC recorders
were introduced at the Firato consumer electronics show
in Amsterdam in 1992.
DCC used a Magneto-Resistive (MR) head, which was fixed to the mechanism of the
player/recorder, unlike rotary heads that are used in helical scan systems such as DAT orVHS to
increase head-to-tape speed
Phillips DCC-900 : Digital
Compact Cassette recorder
More on DCC
MiniDisc was announced by Sony in September 1992 and released that November for sale
in Japan and in December for the USA and Europe. The music format was originally based
exclusively on ATRAC audio data compression, but the option of linear PCM digital
recording was later introduced to attain audio quality comparable to that of a compact
disc. MiniDiscs were very popular in Japan but made a limited impact elsewhere.
MD Data, a version for storing computer data, was
announced by Sony in 1993 but never gained significant
ground. Its media were incompatible with standard audio
MiniDiscs, which has been cited as one of the main reasons
behind the format's failure. MiniDisc has a feature that
prevents disc skipping under all but the most extreme
conditions. Older CD players had once been a source of
annoyance to users as they were prone to mistracking from
vibration and shock.
The size of the buffer varies by model.The data structure and operation of a MiniDisc is similar
to that of a computer's hard disk drive.The bulk of the disc contains data pertaining to the
music itself, and a small section contains theTable of Contents.Tracks and discs can be
named, and may easily be added, erased, combined and divided, and their preferred order of
playback modified. Erased tracks are not actually erased at the time.When a disc becomes
full, the recorder can simply slot track data into sections where erased tracks reside
MiniDisc solved this problem by reading the data into a memory buffer at a higher speed than
was required before being read out to the digital-to-analogue converter at the standard rate
required by the format.
DVD-Audio offers many possible configurations of audio channels, ranging from single-
channel mono to 5.1-channel surround sound, at various sampling frequencies and sample
rates. Compared to the Compact Disc, the much higher capacity DVD format enables the
inclusion of either:
-Considerably more music (with respect to total running time and quantity of songs) or
-Far higher audio quality, reflected by higher linear sampling rates and higher bit-per-
sample resolution, and/or
-Additional channels for spatial sound reproduction.
DVD-Audio (DVD A)
The fidelity of the upsampled audio
will be limited by the source material
quality, when the master recording is
in digital format, and may not exceed
the quality of existing CD releases of
the same albums. DVD-Audio supports
bit depths up to 24-bit and sample
rates up to 192 kHz, while CD audio is
16-bit, 44.1 kHz. DVD-Audio discs may
optionally employ a copy protection
mechanism called Content Protection
for Prerecorded Media (CPPM).
DVD A being used as home theatre
More on DVD Audio