Perceptual Audio Coding

Perceptual Audio Coding (PAC) is an algorithm, like MPEG's MP3 standard, used to compress digital audio by removing extraneous information not perceived by most people. It is used by Sirius for their DARS service, and Ibiquity has been testing it for their IBOC digital radio upgrade for FM.

The term is sometimes used non-capitalized, to describe all lossy compression formats for audio.

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Pac is also a handle sometimes used by rapper Tupac Shakur.

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PAC is also an acronym for political action committee.