Adaptive TRansform Acoustic Coding
Synonyms
ATRAC
(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.