standard sound reproduction used in most theaters that uses a minimum of six channels.

Developed by Dolby in the early 70s, Dolby Stereo produces 4 channel sound with three channels of sound in the front (left and right for music and effects and centre for dialogue) and a surround channel for effects and atmospheres.

A system of noise-reduction, equalization, and surround sound, used for motion-picture sound tracks.

Dolby Laboratories' umbrella term for its film sound technologies.

Dolby Stereo (or Dolby Analog) was the original analog optical technology developed by Dolby Laboratories for 35 mm prints in 1976.