The USAF claims supersonic aircraft on secret missions are causing the booms, yet such mysterious booms are being reported worldwide.
In mid-November, shocked residents in Alabama were left so alarmed by the noise they even called the cops to investigate.
They dubbed it the "Bama Boom", saying it was so powerful it actually shook houses and left windows rattling.
However, NASA and the US Geological Survey said they had no idea what was causing the booms, saying they could only theorise.
Comment: The sounds have been heard in numerous areas of Alabama. The National Weather Service has said that it did not appear that earthquakes were involved. Meteorites and sonic booms have been floated as possible causes.
But now it is thought supersonic aircraft are most likely responsible after more booms were heard on Wednesday in in Texas.
After a number of loud explosions, a Fort Hood spokesman confirmed live-fire exercises and B-1 "Lancer" bombers were responsible.
The US Air Force has not confirmed or denied whether its jets were responsible on previous occasions, but occurrences of the booms seem to match up with days military exercises were taking place.
A boom heard on May 7 in Florida was only later confirmed to be caused by supersonic flight testing.
The US Air Force revealed the secret military mission that ended at Kennedy Space Centre was the cause of the sound.
The booms have also been heard in other parts of the world, including the Middle East and Europe.
Comment: These loud booms often coincide with earthquake like shocks and are rattling nerves around the world with increasing regularity. They are probably associated with the dramatic rise of fireballs and meteors which have been increasing each year exponentially!
- 64 mysterious booms heard all over the world this year. Why?
- Mysterious 'skyquakes' continue around the world with few answers to their origins
For more background on the increased asteroid and fireball activity - including its causes, effects, and role in human history, see: Earth Changes and the Human-Cosmic Connection.