Last night my area got hit with a hum. A strange noise I had never heard before. It was enough to wake me up at 00:15am and lasted about half an hour.
It was a pulsating type noise, similar in sound to the first noise you hear in the video below but not as constant.
My instinct told me that it was the sound of a tunnelling machine, cutting through rock. (We have large deposits of limestone in the area.) Yet, that didn’t make sense, since there are no mine workings in the area and the population is around 30,000 people. Quite an urban environment.
I am not sure if the sound stopped or if I got used to the rhythm of the pulse and just fell back asleep.
However, today I decided to search online to see if anyone else in the community had encountered something similar.
That was when I learned about the Bristol Hum.
Also, there is a World Hum and Database Project website. So it really does appear to be a global phenomenon.
It seems that nobody has a clue what the cause of the sound is, or if they do, they are not letting on.
Have you heard the hum where you live?