Untitled Sighting

Me and my roomate were watching a movie, when we heard this ungodly sound from out side.  It was this wierd wail/howl/scream.  It started out real low and guttural, like a cheap frankenstein groan, and then shot up the octave range to an amazing high pitch wavery howl.  It sounded like a cross between a woman screaming and a fire siren.  It got quiet for a mintue and the the screaming started up again, but it sound like it had moved closer.  All the dogs in the neighborhood went nuts.  They sounded like they were dying or something.  After the second wail stoppped I worked up the nerve to open the door and go outside.  It smelled horrible outside, and I got the distinct impression I was being watched.  So, I went back inside, and hoped that what ever it was, it was gone.