http://superuser.com/questions/10722...-samsung-files
Some quick research suggests this type of file is actually a voicemail recording from some software called "Jet-VoiceMail" by Cowon America.They provide some software called JetAudio with two versions available (Free and paid for Pro version). The download page on their site suggests that the free version is capable of opening any audio format and converting it to a more popular format (I would suggest WAV or OGG).

оно?