ADPCM
Adaptive Differential Pulse Code Modulation

This method of encoding sound data files takes up less storage space than the regular PCM format used by WAV and AIFF files--and CD audio for that matter. ADPCM comes in more than one flavor: IMA's ADPCM, for example, is used on the Sony Mini Disc to cram more data onto a smaller platter; Microsoft ADPCM is used as part of Windows 95's canon of audio codecs.

See also: AIFF, codec, PCM, WAV