How to Extract Sound Track from MP4 to WAV File
Developed by Apple company, M4R, also called MPEG-4 Ringtone, is a audio file format used exclusively as ringtone in iPhone device and Its audio codec is AAC. You are allowed to customize and create the ringtone with the purchased songs from iTunes library which are converted from other audio formats, say, MP3 to M4R and then transferred to your iPhone. You can also rename the M4A files to M4R file extension and then sync to iPhone device using iTunes. With M4R, you are able to experience the high quality ringtone with reduced audio file size.
Related Article: How to Convert MP3 to Create M4R iPhone Ringtone
Facts about M4R
What devices or program support M4R