A loud sound was heard in an area of Wisconsin around Janesville, in Green and Rock counties on Saturday night. It has been described as a roar that lasted longer and was louder than the sound of a plane. A search of the local weather reports does not reveal any reason for the sound to have been meteorological. It stands as yet along in the now long string of unexplained sounds being reported in the United States and around the world.

Story Source:
http://www.channel3000.com/news/Report-No-explanation-for-loud-roar-heard-Sunday-night/32462400