Surround sound
Surround sound encompasses a range of
techniques for enriching the sound reproduc-
tion quality of an audio source with audio
channels reproduced via additional, discrete
speakers. The three-dimensional (3D) sphere
of human hearing can be virtually achieved
with audio channels above and below the
listener. To that end, the multichannel sur-
round
sound application
encircles
the
audience
(left-surround,
right-surround,
back-surround), as opposed to "screen chan-
nels" (center, [front] left, and [front] right),
i.e. ca. 360° horizontal plane, 2D).
Surround sound technology is used in
cinema and home theater systems, video
game consoles, personal computers and oth-
er platforms. Commercial surround sound
media include videocassettes, Video DVDs,
and HDTV broadcasts encoded as Dolby Pro
Logic, Dolby Digital, or DTS. Other commer-
cial formats include the competing DVD-
Audio (DVD-A) and Super Audio CD (SACD)
formats, and MP3 Surround. Cinema 5.1 sur-
round formats include Dolby Digital, DTS,
and Sony Dynamic Digital Sound (SDDS).
Most surround sound recordings are cre-
ated by film production companies or video
game producers; however some consumer
camcorders have such capability either built-
in or available separately. Surround sound
technologies can also be used in music to en-
able new methods of artistic expression.
After the failure of quadraphonic audio in the
1970s, multichannel music has slowly been
reintroduced since 1999 with the help of
SACD & DVD-Audio formats. Some AV receiv-
ers, stereophonic systems, and computer
soundcards contain integral digital signal
processors and/or digital audio processors to
simulate surround sound from a stereophonic
source.
History
The first documented use of surround sound
was in 1940, for the Disney studio’s animated
film Fantasia. Its multichannel audio applica-
tion was called ’Fantasound’, comprising
three audio channels and speakers. The
sound was diffused throughout the cinema,
initially by an engineer using some 54 loud-
speakers. The surround sound w