1926: First sound (music and sound effects) in a film, 'Don Juan' using the 'Vitaphone' sound-on-disc system

1927: First film with recorded dialogue, 'The Jazz Singer', using the 'Vitaphone' system

1940: First use of 'surround sound' in a movie: Disney's 'Fantasia', using the 'Fantasound' system

1953: The first four-track (L/C/R/S) magnetic sound system used for Twentieth Century Fox's 'The Robe' (35mm Cinemascope)

1955: The first six-track magnetic sound system used for the film 'Oklahoma!' (70mm Todd-AO: five screen channels, one surround channel)

1975: Dolby Stereo introduced with 'Tommy' (also recorded in the 'Quintaphonic' system), optical Dolby Stereo introduced for 'Lisztomania'

1976: First optical Dolby Stereo Surround soundtrack for 'A Star is Born'

1977: 'Damnation Alley' released in 'Surround 360°'. The format's one and only outing

1978: 'Star Wars' wins the Academy Award for Best Achievement in Sound. Subsequently, every winner until 1994 is a Dolby Stereo film; Limited experimental release of Dolby Stereo 70mm with discrete stereo surround channels (Superman)

1979: First broad release Dolby Stereo 70mm soundtrack with discrete stereo surround channels (Apocalypse Now on 15 screens)

1980: 'Popeye' becomes the first film to use the 'Vistasonic' system

1981: First pre-recorded VHS cassette with a stereo soundtrack (non Hi-Fi, Dolby B NR encoded) released by Pacific Arts

1982: First domestic Dolby Surround decoder, by Surround Sound Inc.

1983: VHS 'Hi-Fi' sound system introduced

1985: 'Fantasia' re-released theatrically with a 2-channel PCM (44.1kHz/16-bit) soundtrack: the first time a PCM soundtrack was used for a theatrical presentation; First Dolby Surround encoded LaserDiscs and videocassettes released

1986: Dolby Stereo SR (Spectral Recording) introduced; NICAM digital stereo sound tested by the BBC; PCM digital audio on LaserDisc

1987: First Dolby Stereo SR films released: Innerspace and Robocop

1990: Kodak's CDS six-channel digital sound system introduced ('Dick Tracy')

1991: Limited experimental release of 'Star Trek 6' in Dolby Digital (in 3 US theatres)

1992: Dolby Digital's national roll-out (US): 'Batman Returns'

1993: DTS introduced in 'Jurassic Park', SDDS introduced in 'Last Action Hero'; AC-3 formally adopted as HDTV's audio standard

1994: First dual-format film released ('Heaven and Earth' with both DTS and Dolby Digital soundtracks on the same print); First consumer satellite transmission of Dolby Digital AC-3 (DMX for Business: 120 channels of stereo broadcasting)

1995: Domestic (384kbps) Dolby Digital introduced on LaserDisc (NTSC only); 'Die Hard With a Vengeance' released theatrically using all three sound systems (DTS/DD/SDDS)

1996: First DVD-Video discs released in Japan (November, first title: Shinji Ra Munita); Dolby Digital becomes available on DVD; Installed base of Dolby Stereo equipped theatres passes 28,000; Dolby Surround AC-3, Dolby Stereo Digital, Dolby SRD officially renamed 'Dolby Digital'

1997: First DVD-Video discs released in the US (March); 448kbps Dolby Digital available on DVD; DTS becomes available on LaserDisc (January: first title Jurassic Park)

1998: (non-theatrical) DTS DVD released: the made-for-video animated film 'The Legend of Mulan' (not Disney's 'Mulan')

1999: Universal and Image begin releasing theatrical DTS DVDs (January): 'Dances with Wolves' (Image), 'Dante's Peak', 'Waterworld', 'The Shadow', 'Liar Liar', 'Babe', 'Daylight' (Universal); installed base of theatrical Dolby Digital decoders passes 20,000; 'Star Wars: Episode One: The Phantom Menace' released in Dolby Digital Surround EX: also shown with uncompressed PCM soundtracks (44.1kHz/24-bit) in four US theatres. First 754kbps DTS DVD title released (November, Saving Private Ryan)

2000: First DTS-ES Discrete 6.1 DVD released (The Haunting)

2002: Dolby Digital 'Sonic Whole Overhead Sound' system demonstrated for the limited re-release of We Were Soldiers.