ADPCM

ADPCM, Adaptive Differential Pulse Code Modulation. This method of coding sound files takes up less storage space than the classic PCM format used for WAV and AIFF files and audio CDs. There are several variants. IMA (Interactive Multimedia Association) ADPCM is used on the Sony MiniDisc to get more data onto a smaller disk; the Microsoft ADPCM format is used in the Windows XP audio codecs. Many mp3 players use ADPCM for voice recording.