AC3 is an audio format designed by Dolby Digital to offer surround sound listening. This format is available on most Blu-ray and DVD media files and is played using a Dolby Digital DVD Player. Interestingly, AC3 can be output in up to six speakers of a home stereo system. On a computer, AC3 can be opened on VLC Media Player, Apple QuickTime Player, and Windows Media Player.
VLC Media Player Apple QuickTime Player Windows Media Player
AAX (Atom Asset Exchange) is an audio file format for storing sound-based products from Audible Incorporated. Typically, AAX files are DRM protected, although they can be transcoded to other common formats such as MP3 using a licensed program like Wondershare UniConverter.