AT3 - ATRAC3 Audio File
This is an audio file that is created with the Sony Adaptive Transform Acoustic Coding 3 (ATRAC3) compression format. It has been designed to be stored and played back on portable media devices which include Sony CD and MP3/MP4 players. It can also be used with the Sony Playstation Portable (PSP) as well as Sony Ericsson cell phones. This file type may also use the AA3 or OMG extensions which denote the files contain Digital Rights Management (DRM) information and may be copy protected.