Some people prefer using other VON products for in-game voice communication, such as Roger Wilco. Sometimes, however, when OFP's VON is enabled, it affects the sound quality of some of these other VON products.
OFP player RedRogue says that it's easy to disable OFP's VON, if you don't want to use it. Simply disconnect your PC's microphone, run the OFP preferences program, click on VOICE SETUP button and run the Sound Hardware Test Wizzard. The test will determine that you have no microphone and internally disable OFP's VON feature.
Another way to disable OFP's VON is to edit file Flashpoint.cfg and add the following line:
If you've got a separate copy of file Flashpoint.cfg for use when hosting a dedicated sever, you can add the same line there, too.