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The optical audio track

At the beginning movies
where just a visual experience. The only sound(track) was the music (a band)
played to give the audience a certain atmosphere while watching a movie. Then
in 1909 Eugene Lauste, a Belgian who lived in England, developed the first 'photographic
sound track'¹,
a technique used even today to capture audio beside the film cell. The newsreels
in the 20's already used this technique.
One of the first experiments to
make music more stereophonic was done by Alan Blumlein at EMI Records in 1923
because of the lack of other mediums.
The first popular feature movie with
sound used a sort of LP to take advantage of the 'soundtrack'. It was called
'The Jazz Singer'. The problem with that one was: the LP had the
same playing time as the movie ribbon, so the projectionist had to synchronize
both. With the photographic sound track it was much easier, because it was attached
to the ribbon and need not to be synchronized. That is why photographic sound catch
on until today.

In 1938, Walt Disney introduced
a new sound-system called
'Fantasound', this system was initiated along with
the movie 'Fantasia'. But it was to complex to succeed. Fantasound
used a second movie ribbon (the follower) with three photographic sound tracks and
a control track on it².
The follower had to be synchronized with the feature movie, too. Today you can
buy Fantasia in Dolby Stereo.
But Fantasound was only one of many other
attempts to make the sound match the broader picture, that has developed over
the years. For example
'Cinerama', a system with three projectors for the
picture and a fourth one for a follower with seven audio tracks, which referring
to the immense expense had no success either.

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The magnetic audio track

While the photographic sound track established itself, another method approached on the market. The
audio recording on 'magnetic tapes'. An oxide track was attached
to the 35mm celluloid and was then the sound was written down on it just like
on a cassette tape. With this new method four audio tracks where possible. One
channel for left, front and center and one for the effects (just the effects,
in contrast to systems today). Each channel got a speaker and the effects channel
got several speakers around the back of the spectators. The first feature movie
with this so called 'CinemaScope'³ system was
'The Rope' by Alfred Hitchcock in 1952.
Some other systems appeared and disappeared
on the market, too. For example, 'Todd AO', with a 70mm movie
ribbon and six magnetic audio tracks, or 'Sensurround' a system
that basically used impressive subwoofers⁴,
which sometimes let fall the plaster from the ceiling.
But magnetic tracks
on celluloid had two major disadvantages: First, they were very expensive. A
70mm movie with magnetic tracks cost about 20 times the price of a 35mm movie
with an photographic sound track. Second, the oxide crumbled away after several times
of playing.

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Dolby^® Stereo

In 1974 the Dolby Laboratories
introduced Dolby Stereo to the media. But it was not fully operational until
1976, when 'A Star Is Born' with Barbara Streisand⁵
and Kris Kristofferson⁶
appeared in the cinemas. It was the first movie with the so called Dolby Stereo
(optical)⁷
system.

Dolby Stereo consisted
of two seperate techniques:

1. 'Dolby-A noise
   reduction'
2. 'Dolby-MP⁸-Matrix encoder'

Dolby-A was developed in
the late 60's by the sound engineer Ray Dolby. Dolby originally created it for
the use with tape recordings⁹,
but it worked well with movies, too. The Dolby-MP-Matrix encoder was constructed
by Ioan Allen. It enabled the Dolby engieers to put four audio channels into
two photographic sound tracks, which means it was now possible to produce a cheap
multi-channel soundtrack on a 35mm film¹⁰.A
medium the most cinemas were able to play.
Dolby Stereo's triumphant advance
began in 1977 with the movies 'Star Wars' and 'Close Encounter
Of The 3rd Kind', both movies who took full advantage of this new system.

1986, the Dolby labs extended
Dolby Stereo with the SR¹¹-technique
which enhanced the recording quality, so it nearly reached the quality of 70mm
movies. One of the first films which used Dolby SR was the action movie 'Robocop'
by Paul Verhoeven in 1988.

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Digital sound systems

In 1991 Kodak¹² changed the
scenery of cinema sound with the movie 'Dick Tracy' and their
new digital system 'CDS'¹³, which didn't succeed
because, for example, it replaced the analog audio. But it startled Dolby and
in a hurry they announced their own digital sound system, then called 'SR.D'.
However it took one year before it had finally premiere with 'Batman Returns'
in 1992. Warned by the CDS desaster, Dolby didn't replace the analog track,
but put the bits and bytes between the perforation. The advantage of this technique
is that every cinema in the world could play one and the same copy of the film,
because it contains everything on one movie ribbon. A simple equipped cinema
could play it in mono, the better in stereo and the up-to-date ones with digital
sound. This combination of the SR optical audio and the digital recording led
to the name SR.D, which was later replaced with 'DSD'¹⁴. Later they let
the word Stereo fall flat, so today it is simply called 'Dolby Digital'

Until today several new
digital sound systems appeared on the market.On the one hand there is 'DTS'¹⁵, which had its
breakthrough with Steven Spielbergs megaseller 'Jurassic Park' in
1993. On the other hand we have 'SDDS'¹⁶
Last
year (1999) a new Dolby release showed up: 'Dolby Digital EX'

Dolby Digital EX adds a new channel to the six¹⁷existing
channels: the rear center. First it could be seen in George Lucas' sequel 'Star
Wars: Episode I - The Phantom Menace'. Some other movies with this new
standard are 'Austin Powers 2: The Spy Who Shagged ME' and 'The
Haunting', for example.

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The enhancement in sound quality: THX

'THX'¹⁸is not a
sound system, but a system to improve the audiovisual quality of cinemas. It
works with every system that is used today, simply because it is just some kind
of quality seal. THX is a rulebook for the fidelity of reproduction of a movie
theater. A theater with the THX seal is inspected to keep the standards of high
quality movie reproduction in sound and picture every 12 months.

Here a short extract of
THX's history:

• In 1982 the
  first THX mixing room opens at Lucasfilm.
• 1983 THX Division
  of Lucasfilm, Ltd is created;
  two THX theatres open in time for the release
  of 'RETURN OF THE JEDI' in the same year
• 1990 Home THX
  Program is introduced
• 1993 THX Laser
  Disc Program is created; quality control services are offered to studios for
  films during video disc production
• 1996 Laser Disc
  Program expands to include videotape and DVD. Name is changed to THX Digital
  Mastering Program
• 1997 More than
  1,600 certified movie theatres and mixing rooms are created around the world
• 1998 THX announces
  certification standard for DVD players.

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