Low frequency noise/vibrations in household 2017-03-01 11:34:53 Since some time, might be a year or even two, I'm annoyed by very low frequency noise hearable in the house. By ear it is somewhere around 35-40 Hz, it is most audible in bedroom upstairs (probably a question of resonance). At night I can clearly hear when it appears and disappears (several hours periods), I don't sense it at day (not sure if due to masking by daytime noises or if source is off).House is on a hill, outside of city, the source of noise surely doesn't come from anything inside or neighbourhood - I excluded heating, fridge, there's no big air conditioning around, nor high voltage lines/transformers, train lines, big roads, etc.There's a market and some small industry several hundreds meters away, but I think it's too far for common industry diesel engines to pollute with vibrations that far.A couple of kilometers away they bore for gas (3,5 km deep), I thought that this might be the source but it doesn't take ~2 years to dig such hole does it? And I guess that after drilling, the extraction of gas itself shouldn't cause such long-range noise?There's also dynamometer of aircraft engines which is said to work 24/7 but it is 10 kilometers away...Any ideas what it might be? Is there any not expensive hardware which could measure the frequency and level of such low frequency noise? Maybe one night I'd drive around with something like that to locate the source (hoping it's not hell digging up, or aliens ).