Proper noun
ATRAC
Initialism of Adaptive Transform Acoustic Coding: a family of proprietary audio compression algorithms developed by Sony and originally used for MiniDiscs.
Contrary to most Walkman lines, Sony Ericsson Walkman Phones did not support Sony's proprietary audio format, ATRAC (with all of its variants, except certain Japanese models supporting ATRAC). Source: Internet
However, as Sony only pushed ATRAC compatibility in Sony Ericsson Walkman series phones in the Japanese market, it is not supported in GSM UMTS market phones. Source: Internet
ATRAC allowed a relatively small disc like MiniDisc to have the same running time as CD while storing audio information with minimal loss in perceptible quality. Source: Internet
As in previous ATRAC versions, gain control is used to control preecho rather than variable sized transforms, although different MDCT windows are apparently possible. Source: Internet
Hi-MD also supports both ATRAC3 and ATRAC3plus in varying bitrates, but not the original ATRAC. Source: Internet
MiniDisc was the first commercial product to incorporate ATRAC in 1992. Source: Internet