Dolby Stereo
{'<entity_0>': 'Dolby Laboratories', '<entity_1>': 'Center channel', '<entity_2>': 'matrix decoder', '<entity_3>': 'Dolby Stereo'}
[['Dolby Stereo', 'uses', 'Center channel'], ['Dolby Stereo', 'developer', 'Dolby Laboratories'], ['Dolby Stereo', 'uses', 'matrix decoder']]
<entity_3> is a sound format made by <entity_0>. The optical soundtrack on a <entity_3> encoded 35 mm film carries not only left and right tracks for stereophonic sound, but also—through a matrix decoding system (Dolby Motion Picture matrix or Dolby MP) similar to that developed for "quadraphonic" or "quad" sound in the 1970s—a third <entity_1>, and a fourth surround channel for speakers on the sides and rear of the theater for ambient sound and special effects. <entity_0> solution to the center-channel problem was to use a "directionally enhanced" <entity_2>, based on those developed for domestic "Quadraphonic" systems, to recover a <entity_1> from left and right channels recorded on the film. Dolby Surround was the earliest consumer version of <entity_0> multichannel analog film sound format <entity_3>. The SSM-2125 is a complete <entity_3> <entity_2> (except for the surround delay) on a single chip, it allowed domestic decoders which used the same logic system found in professional decoders to be marketed to the consumer.
['sound recording']