Is there any bridge or other heavy construction going on nearby? Pile driving can create booming noises that can carry a long way, depending on soil type. I don't know just where you are, but pile driving is pretty common in areas where there is shipping, rivers, etc. Lots of times, people don't know about that kind of construction that may be going on not far from them.
If you're in the Mobile area, Google Pile Driving Mobile, AL. You'll find three major companies that do that kind of construction work. Give them a call and see where they're working right now. Could be something not too far from your home.