My neighbour has been hearing a low level hum, similar to a generator, for weeks. Initially she heard it only in the house, but she can now hear it outside occasionally. Its not constant, but can last for 90mins. She has asked other neighbours, nothing.
I thought nothing of it, until a few weeks ago, i heard it at around 330am, i have heard nothing since.
I spoke to her a few days ago (at a distance of course), and she is still hearing it occasionally, and i am concerned its driving her a little stir crazy.
Anyone else heard it ? or experienced similar in the past which may give her an answer.