Almost, I was thinking of the Windsor hum. Thanks!

More interesting sources in case anyone is interested:

[0] https://en.wikipedia.org/wiki/The_Hum

[1] https://en.wikipedia.org/wiki/List_of_unexplained_sounds

[2] https://en.wikipedia.org/wiki/Skyquake

[3] https://en.wikipedia.org/wiki/Cryoseism