What is the difference between .m4r and .htk?
- Extension
 - .m4r
 - .htk
 
- Format
 - Binary
 - Binary
 
- Category
 - Audio
 - Audio
 
- Developer
 - Apple Inc.
 - Cambridge University's Speech Group.
 
- Description
 - M4R is an iTunes ringtone file that stores mono channel audio. They are identical to the M4A format files only that they are correctly used for ringtones.
 - Single channel 16-bit PCM format used by HTK, a toolkit for building Hidden Markov Model speech processing tools.
 
- MIME Type
 - audio/x-m4r
 - application/x-htk
 
- Sample
 - sample.htk
 
- Wikipedia
 - .m4r on Wikipedia
 - .htk on Wikipedia