Poster produced by MGM to advertise Dolby Stereo sound system, c. 1976

Dolby Labs was founded by Ray Dolby (1933–2013) in London, United Kingdom, in 1965. In the same year, he invented the Dolby Noise Reduction System, a form of audio signal processing for reducing the background hissing sound on audio tape recordings.

Dolby also sought to improve film sound and the first film with Dolby sound was A Clockwork Orange in 1971. In 1975, Dolby released Dolby Stereo, which included a noise reduction system in addition to more audio channels.