PCM audio signals are digital audio signals that have been converted from standard audio waves with minimal compression. This type of audio technology is most commonly used on digital audio formats, such as CDs and audio DVDs. PCM audio signals are converted to analog form when played through loudspeakers.
PCM audio signals are generated through a process of sampling analog audio signals at uniform intervals. Each audio sample is then quantized to either a linear value or a varying value level according to the amplitude of the audio wave. The invention of PCM audio technology is credited in the United States to Bernard M. Oliver and Claude Shannon, according to a patent granted in 1956.