As a non degree-holding "consultant",[5] 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.[5]
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.[9]
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 audible level of tape hiss.[9] 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]
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 (1971), which used Dolby noise reduction on all pre-mixes and masters, but a conventional optical sound track on release prints. 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 in 1976. In fewer than ten years, 6,000 cinemas worldwide were equipped to use Dolby Stereo sound.
Dolby died of leukemia on September 12, 2013, at his home in San Francisco at the age of 80.[13] Dolby was survived by his wife Dagmar, two sons, Tom and David, and four grandchildren.[14][15] Kevin Yeaman, president and chief executive of Dolby Laboratories, said, "Today we lost a friend, mentor and true visionary."[14]Neil Portnow, president of the National Academy of Recording Arts and Sciences, said Dolby had "changed the way we listen to music and movies for nearly 50 years" and that Dolby's "technologies have become an essential part of the creative process for recording artists and filmmakers, ensuring his remarkable legacy for generations to come."[16]
In his will, Dolby bequeathed £35 million to Pembroke College, Cambridge, reportedly the largest single donation received by any college in the university's history.[17] In December 2017 it was announced that his family had donated a further £85m from his estate to Cambridge University's Cavendish Laboratory[18] which funded a physics professorship and the building of the Ray Dolby Centre, to be completed in 2024.[19][20] In 2022, the Dolby Family Fund for Excellence in Physics was expected to fund further academic posts and PhD studentships, as well as an annual symposium.[20]
1983 — SMPTE Progress Medal For his contributions to theater sound and his continuing work in noise reduction and quality improvements in audio and video systems and as a prime inventor of the videotape recorder[23]
U.S. patent 3,631,365, Frequency selective, symmetric signal compressor/expander (Dolby noise reduction); application filed October 20,1969, patent granted December 28, 1971
