Quiet outside. Rebooted device. Any idea?
I have absolutely no idea what that could be. Audio feedback of some sort, maybe?
Sounds like someone in the parking lot needs to replace an idler pulley on their vehicle.
Is this sound always there?
The sound, sounds amazingly like a switching mode power supply when heard via a radio… Try killing other devices and lights close to the camera to see if the sound ends.
I don’t know what you guys are talking about. To me that just sounds like birdsong / crickets being squelched / noise canceled periodically by the camera mic circuitry.