So there's a weird humming noise in my apartment that pops out for a few hours a day and would keep me awake. I was hoping you guys might have heard of it and can tell me what the hell is causing this. My oscilloscope tells me it's 120Hz so I recreated this audio that my flatmate and I agree is pretty spot on:
https://soundcloud.com/user-898083128/humming-noise-re-creation
This has been driving me crazy for months so thanks in advance for your help!
edit: I live in Boston, MA, and the AC is 60Hz if that's relevant at all