I've been hearing this low pitched hum in my area of Melbourne for the last two weeks. It's been driving me nuts. To me it's not even subtle. but no one else seems to hear it.
They've cranked it up to day, I can feel it right through my body. Like I'll wake up thinking my heart's racing, then realise that's not my heart, that's the machine again. It's an irregular heart beat that speeds up and slows down.
Do you have any recording equipment? Try to figure out the fingerprint so others can try to replicate