Anyways, as of late, (this last night, beginning around 3 A.M.) I began hearing an odd rumbling sound, similar to a jet engine idling, or prolonged thunder directly overhead while outside smoking a cigarette. … Here is where it gets weird, in the slightly raised light i could see that the sky was not visible at all over the clouds. …. I step outside, with a couple of cars driving around so the noise seemed quieter, but more bass heavy. …. Car bomb kills nuke scientist in Iran … …

See the article here:
An odd revelation concerning the rumbling/buzzing sound …