A headerless file of Dialogic/OKI ADPCM audio data commonly comes with the extension .vox. This ADPCM data has 12-bit precision packed into only 4-bits.
is the most common format for storing audio. Almost any player on any platform can open mp3 files. The audio is compressed with loss of quality, but the loss is negligible for the typical user, and the file size is usually less than that of the original files.