I'm shooting footage on a college campus using a wired external shotgun. In certain places on campus, there's an occasional buzz--like someone using a sped-up morse code--followed by a few seconds of thumping. It doesn't happen all over campus, and it's not constant. Since the environment is a college campus, there's a ton of stuff "in the air": phones, internet, the campus network, security guards on radios... First, could these be the causes of the interference, and if so, is there something to do about it?
Thanks for any advice.