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
MP3 is a standard audio format developed by Moving Picture Experts Group and uses MPEG-1 and MPEG-2 standardizations. MP3 uses lossy data compression, meaning that it loses quality over time. This sound format comes with a .mp3 filename extension and is today the most common audio format on websites and multimedia players.
Windows Media Player iTunes, Mplayer VLC Media Player