(ATRAC) An audio compression algorithm, iNTroduced by Sony for its Mini Disk, which relies on the masking of low-amplitude frequency componeNTs by temporaly adjaceNT high-amplitude componeNTs. ATRAC consists of a three-band subband encoder (0...5.5, 5.5...11, 11...22 kHz) and a MDCT based transformation encoder. [Does Sony Minidisk use ADPCM?] (2001-12-13)