Two South Carolina witnesses in Greenwood report a large, black, oval-shaped object moving overhead with four lights that emitted the sound of a "dog whistle", according to March 8, 2011, testimony from the Mutual UFO Network (MUFON) witness reporting database.
"As it got closer the sound got louder," the witness stated. "I also saw what I thought might be some sort of girders or support structure on the underside of the vehicle. I am enclosing a drawing of the underside of the vehicle in this report."
The object moved in one direction during the entire sightings and seemed to be slower than a jet and faster than "any lighter than air craft I am aware of."
The witness states that others in the area also saw the same object.
via Oval object emitted sound of ’dog whistle’ - National ufo | Examiner.com.