I've successfully use my F8-ZOOM and Sennheiser G3/G4 lavaliers on several outdoor assignments resulting in very clean audio capture. I recently used the same F8-ZOOM and G3/G4 lavalier setup in a indoor setup where there was a panel of professional people at a table discussing their specialty topics. I took every professional precaution that a good audio person should take, including "Scan New Frequencies" on location prior to video rolling.
Even though there was quiet on the set after the call of "ACTION", because of the shear boredom of the panel discussion, several crew members were STREAMING their choice of entertainment (football, music, Tv shows, etc.,) with their CELL PHONES and headphones.
COULD THE USE OF THESE CELL PHONES during my audio capture, cause intermittent, random, unwanted, cracking, hissing, static noice during my audio capture