In my offices Conference room we have an expensive AV system with Microphones in the ceilings (im unsure of brand) and for calls we use join.me. On our side people complain of our audio crackling and sounds of something rubbing against mic. Sometimes it happens sometimes it does not, we have tried changing all the settings, whether through the app or PC and messing with audio/voice settings. We have even taken into account turning off the AC fan in the room and etc. could this also be an issue with the USB chord or port connected to the PC?