Strange sound heard in Boca Raton, Florida ( January 2012)

Strange noises in the sky. They seemed to be coming from the east, towards the beach. The moans started to occur around 12 minutes before i could fetch my camera and stopped while i was recording. My dog was freaking out and the neighbors dog started to bark as well. This is some creepy stuff I hope it is not a government experiment or conspiracy. Some people say it might be from a cruise ship or someone playing a prank. Has anyone else been hearing these strange noises br, br,