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.
Files containing the AMB extension are known as AIMMS Model Files as they refer to the models that the AIMMS (Advanced Integrated Multidimensional Modeling Software) created. The AMB file extension was developed by Paragon Decision Technology and the files with this extension are categorized as data files. The data that these AMB files contain are procedures, identifier declarations as well as core model functions. These files are also based on AIMMS modeling proprietary language wherein these files are saved with the AIMMS project (.PRJ) file it is associated with.