Boxoffice-June.1995

qiialiU' of the sound.'
BoxomcE: Describe the ciieation of
your first noise reduction system.
DOLBY: People had been designing
noise reduction systems for 30 years when
I
started to work on this project. From the
mid-1 930s, people had been trying to crack
this problem, but they overlooked one crucial
fact, and that is that the noise that you
want to reduce is really very, very tiny in
comparison to the loudest signals that you
are dealing with. Typically, noise is only one
percent or less of flie amplitude of the loudest
sounds. The mistake that was consistently
made was that [other engineers had]
sent the whole signal through a compression
process [to get at fliis one percent], and
that distorted and damaged the entire signal,
and gave noise reduction systems a bad
name. The studios had tried dozens ofthem,
and none of them worked to their satisfaction,
so it began to be felt that no one would
ever solve this problem.
I
hit on the idea of sending the high-level
signals straight through, of not doing any-
"In so many ways, we take
low grade performance as
normal because we 're so
used to it.
For example, the
telephone gives us a tinny
sound that 's distorted and
filled with noise. Yet we
accept the telephone, and
there is no great urge or
Founded
Dolby: 30 Years of Sound Ideas
in London in
by John F. Allen
Special to Boxoffice
1 965 with only four assistants, Ray Dolby's Dolby Laboratories
has grown into an international manufacturing and licensing business with offices in
England, the United States as well as Japan. Annual revenues now exceed $40 million.
Dolby's core business has been the development and marketing of products which reduce
or eliminate the audibility of noise associated with recording and transmission systems. In
addition to a record of elegant engineering, the company's success is equally owed to a small
dedicated staff of application specialists who provide (often in person) technicians around
the world with help in using what has become a wide range of Dolby products.
The first noise reduction system was completed in the summer of 1965. Called "A type",
this development became the foundation upon which Dolby built its products for the
recording, television and motion picture industries. The type "A" system was first used with
a commercial recording in 1 966. The first long playing record mastered with Dolby "A" was
released in November, 1 966. Today, over 1 70,000 channels of "A" type have been sold.
1967 saw the first development of a more economical consumer noise reduction system
known as "B" type and subsequent licensing activities. The "B" type system revolutionized
the use of the audio cassette and changed the way we bought prerecorded music. Today,
over 500 million products utilizing a Dolby circuit have been produced worldwide.
By 1970, Dolby had begun to make small inroads into the motion picture industry. In
December of that year, "A Clockwork Orange" became the first conventional optical
soundtrack release mastered with Dolby noise reduction. By 1 976, Dolby's stereo optical
soundtrack including a surround channel had been developed and was in use in theatres.
This soundtrack made it practical to exhibit motion pictures in stereo without the cost and
reliability problems associated with older magnetic striping techniques.
Six years in development, Dolby Spectral Recording (SR) was introduced In 1986. The SR
system took analog recordings and optical motion picture soundtracks to the practical limit
of their performance capabilities, giving a new lease on life for analog studio facilities facing
competition from digital recorders and other devices. Since its introduction, SR has been
installed in over 7,000 theatres, over 90,000 audio channels and used with over 500 releases.
Beginning in 1 985, Dolby Laboratories embarked on research exploring ways to reduce
the number of bits required to store or transmit digital audio. Seven years later, this work
had advanced to such an extent that a six channel, reduced bit rate digital motion picture
optical digital soundtrack, Dolby Digital, was introduced in ten theatres with "Batman
Returns." Today, some 1,700 theatres are equipped with the Dolby Digital process.
Ray Dolby's legendary "little" sound company has earned its success, one could say, the
old fashioned way: one well-conceived product and one satisfied customer at a time.
Copyright 1995, John F. Allett. All RigJits Reserved.
push to improve that.
That's the way movie sound
was back in the 1960s.
thing to diese signals. I devised a side chain
tliat could identify the existence ofvery low
level signals [containing audible noise], and
which allowed low-level signals to pass
through to be processed. If a high level
signal came along, this side chain would
block the high level signals fi'om getting
through. And then I added a 'subtractor,' so
that the high level signals gomg to the main
signal path and the low level signals going
to the side chain. ..these two signals with
noise join up in the subtractor and cancel
each other out. Its the cancellation process
that reduces the noise, and whenever the
signal is loud, the cancellation effect di,sai>
pears, because the signal is prevented from
getting through the side chain. One thing
that's oflen misunderstood about this process
is that its perfectly complementary, in
other words, the plaj'back half exacdy undoes
what the recording half did.
Boxoffice: Where fUni use of Dolby
processing is concerned die ixn'olutionary
moment is 'Star Wars,' isn't it?
boLBY: Well, I don't know. That was our
tenth or twelfth film. But that's the one that
popularized our process.
BoxoFHCE: I'd always been under die
impression that was your first film
project, as a matter of fact.
DOLBY: No, no. We were pretty far down
the line when that took place. That was in
1977. We had made mono films for several
years, then we started the stereo process in
about 1973-1974, and then we added surround
in about '75, '76. The Barbra Streisand
film 'A St;ir is Bom,' that was the first one
that used our sunoimd.
Boxoffice: Which mak(\s p(;rfect
senst; beciiuse that was a nuisit;-basc(l
film and as a n^cordin}; artist she would
hav(; b(;en lamiliar t\'i(h \()iir ((^chiiologj'.
I
do want to talk about 'Star Wat's,'
b(;c