PCM (pulse-code modulation)

PCM is the standard representation of uncompressed digital audio: the signal is sampled at a fixed rate and each sample stored as a number — what WAV and AIFF files contain.

PCM is the lingua franca of audio processing; every codec decodes back to it before playback or analysis. 'Uncompressed audio' and 'PCM' are effectively synonyms in practice.

Related terms

Sample rateSample rate is how many times per second an audio signal is measured when converting sound to digital data, in… Bit depthBit depth is how many bits describe each audio sample — 16-bit (CD) gives about 96 dB of dynamic range; 24-bit… Lossless compressionLossless compression (FLAC, ALAC) shrinks audio while preserving it bit-for-bit — decoding restores the exact …