Drives me nuts, sounds like a low, bass, vibrating sound. We live in the country; the closest house is 500 ft away. The only services on the street is cable + electric which I have turned off at the main to rule out any appliances running. I am writing this at 3:00 AM because the noise keeps me awake. My whole family can hear it. There is nothing nearby to be creating this noise. I go outside at night to see if I can find the source, but you cannot hear it outside of the house. We have lived here for 31 years and never heard this sound until about a year ago. What's going on here? Is someone drilling into the ground thousands of miles away and we get the noise and vibration? Because that is what it sounds like. Nuts right! Any ideas?