The Hum is driving me a bit crazy. I first noticed it this year at the cabin and thought it must be a boat/plane that I couldn’t see. Then I heard it at home when the house was quiet and it bothered me especially when trying to fall asleep.
One morning I went outside to try to track down the source and my ears led me to a noisy electrical transformer on a pole nearby. I complained to BC Hydro and to their credit they sent a crew to investigate right away. No follow up though so I assume, and have read, that transformer hum is normal.
Next time at the cabin I heard the hum again. Strange because there is no power at the cabin and I started to think that it could be in my head, i.e., low frequency tinnitus. So I installed an audio spectrum analyzer app on my phone and there it was, as shown in the screenshot above.
At least I know the hum is real and not in my head. I am learning to ignore it.