This is a proprietary format (with a paid license) developed by Matthew T. Ashland. Sound is stored without any loss, but the format isn’t too common because of license restrictions and because the official codecs works only on the Windows platform.

PVF is a special low-bandwidth ADPCM-based digital audio format for recording and storing human speech. A .pvf file contains digitally recorded speech in the PVF format. Such .pvf files were mainly used with legacy voice modems and software-based answering machines. Often, to be used with a specific modem, a .pvf file would have to be converted into the device-specific RMD format. Currently, PVF audio files can still be played with several major media players as well as converted into other formats (like WAV) with multi-format converter tools.