I grew up with the rebel yell. In college I mostly dated and had good friends in the Southern fraternities and its definitely a fearsome cry when a bunch of people are doing it at the same time. :-)
My dad could do a pretty good rebel yell, but his turkey gobble was spot-on hilarious. This reminds me...I need to record him doing these if he still can. Takes a strong pair of lungs!
This also show how it would have sounded with a group of Rebels sounding the yell.