Editing Ray Dolby (section)

== Career ==
As a non degree-holding "consultant",<ref name="racetovideo" /> Dolby played a key role in the effort that led Ampex to unveil their prototype [[Quadruplex videotape]] recorder in April 1956 which soon entered production.<ref name="racetovideo" />

After Cambridge, Dolby acted as a technical advisor to the [[United Nations]] in India until 1965, when he returned to England, where he founded [[Dolby Laboratories]] in London with a staff of four. In that same year, 1965, he invented the [[Dolby noise-reduction system]], a form of [[audio signal processing]] for analog tape recorders. His first U.S. patent application was made in 1969, four years later. The system was first used by [[Decca Records]] in the UK.<ref name="independent">{{cite news|last=Williamson|first=Marcus|url=https://www.independent.co.uk/news/obituaries/ray-dolby-obituary-inventor-whose-noisereduction-technology-transformed-sound-reproduction-8815543.html|title=Ray Dolby obituary: Inventor whose noise-reduction technology transformed sound reproduction|date=13 September 2013|newspaper=[[The Independent]]|author-link=Marcus Williamson}}</ref>

The Dolby B consumer noise-reduction system works by compressing (boosting) low-level high-frequency sounds during recording and expanding (decreasing) them symmetrically during playback, which also decreases inherent tape noise. This reduces the [[psychoacoustics|audible]] level of tape hiss.<ref name="independent" /> The professional Type A system operates on four different frequency bands, and the final SR system on ten.

After his pioneering work with audiotape noise reduction, Dolby sought to improve film sound. As Dolby Laboratories' corporate history explains:{{citation needed|date=March 2021}}

: Upon investigation, Dolby found that many of the limitations in [[optical sound]] stemmed directly from its significantly high background noise. To filter this noise, the high-frequency response of theatre playback systems was deliberately curtailed… To make matters worse, to increase dialogue intelligibility over such systems, sound mixers were recording soundtracks with so much high-frequency pre-emphasis that high distortion resulted.

The first film with Dolby sound was ''[[A Clockwork Orange (film)|A Clockwork Orange]]'' (1971), which used Dolby noise reduction on all pre-mixes and masters, but a conventional optical sound track on release prints. ''[[Callan (film)|Callan]]'' (1974) was the first film with a Dolby-encoded optical soundtrack. The first true LCRS (Left-Center-Right-Surround) soundtrack was encoded on the movie ''[[A Star Is Born (1976 film)|A Star Is Born]]'' in 1976. In fewer than ten years, 6,000 cinemas worldwide were equipped to use Dolby Stereo sound.

Dolby then developed a digital [[surround sound]] [[Audio data compression|compression]] scheme for the cinema. Dolby Stereo Digital (now simply called [[Dolby Digital]]) was first featured on the 1992 film ''[[Batman Returns]]''. Dolby Digital is now found in the [[High-definition television in the United States|HDTV (ATSC) standard of the United States]], [[DVD player]]s, and many satellite-TV and cable-TV receivers.<ref>{{Cite web|url=https://blog.teufelaudio.com/ray-dolby-life-sound/|title=Ray Dolby: A life in sound|date=2016-01-15|website=Teufel Audio Blog|language=en-GB|access-date=2020-03-31}}</ref><ref>{{Cite web|url=https://www.britannica.com/biography/Ray-Dolby|title=Ray Milton Dolby {{!}} American audio engineer and inventor|website=Encyclopedia Britannica|language=en|access-date=2020-03-31}}</ref>

Dolby was a [[Fellow (society)|Fellow]] and past president of the [[Audio Engineering Society]].<ref>{{Cite web|url=https://www.forbes.com/profile/ray-dolby/|title=Ray Dolby|website=Forbes|language=en|access-date=2020-03-31}}</ref>