Adaptive TRansform Acoustic Coding
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Adaptive TRansform Acoustic Coding(algorithm)
(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.