Cinema Digital Sound

Soon after the Kodak acquisition, Cyclotomics launched the first project to record enhanced-quality digitized sound on movie film rather than on a separate magnetic strip, as was then the current standard. This project, which became known as Cinema Digital Sound (CDS), a.k.a. Digital Optical Sound System, entailed challenging synchronization issues due to mechanical jitter and weave. It also provided a very challenging noise environment. Lloyd Welch and I invented and patented a solution to these problems. At Cyclotomics we designed and built a few prototypes. Our business partners in the movie-projector division at Optical Radiation Corp (ORC), led by engineers Howard Flemming (h.flemming@ca.rr.com) and Ron Uhlig, designed a configuration which combined them with new speakers, replicated and deployed them to 60 movie theaters.

Despite its technical success, the marketing of CDS failed to replace the movie theater industry's incumbent, a partnership of Sony and Dolby. Their system included "error-masking", a method of perturbing the audio when the recording was bad so as to make its noisiness less noticeable to human ears. They persuaded the major movie theater chains that the Kodak/Cyclotomics' CDS would be unusable because it lacked any "masking" feature. The mean time between noise bursts sufficiently bad to cause the Sony-Dolby system to mask was short. They believed that such bursts would cause CDS to "click". But in fact, virtually all such bursts were completely corrected by CDS. Our conservative statistical models indicated CDS might emit a click about once every ten years. And this was borne out by the initial results, with 60 theaters operating for months under field conditions with zero clicks. But the Sony-Dolby sales force persuaded their numerous customers to wait for their forthcoming upgrade, which would purportedly "soon" provide even better-quality sound than CDS. The "soon" turned out to be over 5 years, and the quality remained notably inferior. Meanwhile, following a scandal in another division of ORC, the CDS salesforce was overtaken by its own internal management problems, which led to the demise of the movie-projector division of ORC. The market penetration of CDS peaked at 60 theaters.

Although attempts to spin-off ORC's movie projector division into a new company were unsuccessful, its backers did launch a successful effort to get the Motion Picture Academy to award a 1995 Scientific and Engineering Oscar to Howard Flemming and Ron Ulig (formerly of Optical Radiation Corp) for "Cinema Digital Sound" (CDS), a.k.a. "Digital Optical Sound System". They did the CDS "source coding", including the specifications and locations of the speakers and the formatting. The CDS "channel coding", which included synchronization and error correction, was done by Cyclotomics. CDS was invented by Elwyn Berlekamp and Lloyd Welch, US Patent numbers 5,271,021 and 5,271,022.

When one searched the web for "Cinema Digital Sound" in 2017, one found several wildly opposing narratives: one written by Cyclotomics' partner, another written by Sony-Dolby; and a third written by someone in the movie-film-manufacturing division of Kodak. None offered much in the way of quantitative measures of technical performance particulars. Following his retirement, Howard Flemming (h.flemming@ca.rr.com) has embarked on compiling a more complete and accurate history of CDS. I'm hopeful that it may eventually correct and replace the current entry on Wikipedia.

 © 2018 by M Hight