Have you ever heard of the Aztec Death Whistle? It’s a skull-shaped device you blow into . . . and it sounds like someone screaming for their life. It was originally used in wars to scare enemies . . . and also during human sacrifice.
(Search YouTube for “Death Whistle.” He blows the whistle from 0:51 to 1:09. And at 1:22 they recreate what 100 Death Whistles would sound like in battle.)