Have you ever listen to the sound of the Aztec Death Whistle? It's a skull-shaped object you blow into. The sound is just as menacing as its name. It's absolutely gut wrenching, like someone is screaming for their life. It was originally used by the Aztecs in wars to intimidate their enemies and also during human sacrifice. There is also a part of the video that re-creates the sound of stampeding horses and 100 death whistles. Apparently Amazon sells them If you want one for yourself.