The US military uses the river that runs behind my rural property as kind of a track for some kind of supersonic flight. I've heard them for years, with period

The US military uses the river that runs behind my rural property as kind of a track for some kind of supersonic flight. I've heard them for years, with periods of daily activity, but never seen one, for by the time I hear the sonic boom they are gone from view. I don't understand why the military is allowed to do this but nobody else.