AMR (Adaptive Multi-Rate Audio Codec) is a sound compression format that is designed for speech coding. It is today widely used in UMTS (Universal Mobile Telecommunication System) and GSM (Global System for Mobile Communications). Most modern mobile phones can save short sound recording clips in AMR format and can be converted to other standard sound formats using a third-party program like Wondershare UniConverter.
AMR Player Mplayer VLC Media Player QuickTime 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.