We just heard it again on 1/15/2013 from Oak Island, NC. It was a rolling rumble sounding more like thunder than a sonic boom. There were no t-storms in the area at the time either. I may have heard a jet shortly after the "drums" though, so your theory could very well be correct. I'd like to think so rather than it being an earthquake or weather related phenomenon. I would feel better if the military would tell us if it's them.
More information about formatting options