I've got a low frequency hum that has been permeating my environment for years. I have no idea where it is coming from. Low frequencies are especially hard to

I've got a low frequency hum that has been permeating my environment for years. I have no idea where it is coming from. Low frequencies are especially hard to locate by ear due to their omnidirectional nature. I'm pretty sure there is nothing I can do about it. It has messed up my ability to record music though. I used to be able to record and mix in my living room but that has not been possible for many years now without constantly hearing that noise.