In the summer months of 2012 we kept hearing these weird noises outside. It was after midnight, summer and the windows were open, so it was slightly quieter since most people were sleeping. The sound was a mix of a boom, a warble and some kind of hum, similar to the sounds made by the alien ships in the movie "The War of the Worlds". For the 1st week of hearing these strange noises I just assumed that it was the ships down on the docks at Philly (Delaware River) since they are literally only two blocks from my house. But my curiosity got the best of me and when I did a little more investigating I realized that the sounds were not coming from the direction of the ports, they seemed to be all over, and not in the echo way.
War of the Worlds