Low level hum worse at night

[Fandabadobie]

I am experiencing a noise that I can hear at night like a low level humming. I thought it was just my ears and maybe tinnitus, but a friend stayed over and they heard it too. What could it be? When I put my ear to the wall I can hear it.. I can also hear it in the bathroom when I put my ear to the party wall. I don't know them well enough to ask them by it sounds like a generator. What could it be? I'm too high in the loft to expect it to be the sound of their fridge
Any suggestions??

Our Virgin box hums. The sound seems to travel up the wall to our bedroom. Sometimes I have to come downstairs to power it off.

OP, Came across this article which may be of interest? theconversation.com/cracking-the-mystery-of-the-worldwide-hum-60296

Hello, I have had exactly the same problem for several years now, my husband hears it too but it sounds the worse at night in my bed room. Please let me know if there is any way to avoid or stop this...