Where does this come from, and can I check it?

The encoder boosted quiet passages on the print and the decoder turned them down. The figure is taken from Dolby, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a movies & tv fact?

Yes. It sits on the Movies & TV shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Dolby noise reduction hushed optical soundtracks

The encoder boosted quiet passages on the print and the decoder turned them down Dolby A-type, introduced in 1965, split the audio into bands and compressed quiet sounds before recording. On playback the decoder expanded them back, dropping the background hiss with them. A cinema needed a Dolby unit in the booth to hear the improvement. It sits in Mondo's movies & tv collection, one of 200 facts that each trace back to the reference below.

Where this comes from

Dolby

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Technology trivia

More facts like this

Dolby Atmos treats sounds as movable objectsThe mix stores a position for each sound rather than assigning it a speaker Dolby Stereo put four channels on an optical trackThe 1977 release of Star Wars helped make the format widespread Hanna-Barbera made cartoons cheap with limited animationTelevision budgets forced shows to reuse cels and hold frames SDDS hid eight sound channels at the frame edgeSony printed two thin digital strips outside the picture area Audio restoration lifts speech out of hissEngineers sample the noise between words and subtract that pattern from the track The Jazz Singer brought sound to feature filmsWarner Bros. released it in 1927 with synchronised songs and speech

Tags: sound, dolby, 1960s

Dolby noise reduction hushed optical soundtracks: the short answers

Where does this come from, and can I check it?: The encoder boosted quiet passages on the print and the decoder turned them down. The figure is taken from Dolby, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a movies & tv fact?: Yes. It sits on the Movies & TV shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.