NRG Acoustics HJ-17: Surround sound
Multichannel audio is a method of enhancing the sound reproduction
high-quality of any audio source with additional audio channels from
audio speakers that surround the audience (surround channels), providing
sound from a 360 radius in the horizontal plane (2D) as an alternative
to "screen channels" (centre, [front] left, and [front] right)
originating only within the listener's forward arc.
Multichannel audio is portrayed by a listener position or sweet spot
where audio effects performs best, and provides a constant or forward
perspective of the sound field towards listener around this location.
The technique improves the notion of sound spatialization by taking
advantage of sound localization; a listener's ability to know the
location or origin of a noticed sound in direction and distance. This
typically is achieved through the use of multiple discrete audio
channels routed to an array of loudspeakers.
There are numerous surround based formats and techniques, varying in
processing and saving methods together with the number and positioning
more stations.
NRG Acoustics SG-4: Domains of application
Though cinema and soundtracks signify the main purposes of surround
approaches, its scope of application is expansive than that as
multichannel enables creation of an audio-environment for all sorts of
functions. Multichannel techniques may be used to recreate contents as
various as music, speech, synthetic or natural sounds for cinema,
television, transmissions, or pc's. Concerning music content as an
illustration, a live performance may also use multichannel techniques in
the context of an open-air event, of an musical theatre or for
broadcasting; for a film certain techniques are adjusted to movie
theater, or to home (e.g. home cinema systems).
The narrative place is also a content which could be improved upon
through multichannel solutions. This applies mainly to cinema
narratives, much like the dialog of the characters of a film, but can
even be applied to plays for theatre, to a convention, or to blend
voice-based comments in an archeological site or monument. By way of
example, an exhibit may be enhanced with topical background sound of
water, birds, train or machine noise. Topical natural sounds can also be
used in educative programs.
NRG Acoustics A-70 - Additional fields of application include video gaming consoles, personal computers and other platforms.
In this applications, the material would typically be artificial noise
maded by the computer device in interaction with its user. Significant
work has also been done using multichannel surround sound for enhanced
situation knowledge in armed forces and general population safety
applications.
