In the 1990s, archeologists in Mexico City unearthed a 500-year-old skeleton near an ancient Aztec temple—a victim of human sacrifice. A grisly discovery, yes, but perhaps even more chilling was what the beheaded skeleton was holding: two small whistles, one in the shape of a skull. When a researcher blew into one of the tiny instruments, the horrifying sounds that emerged immediately captivated imaginations. One scholar described the noise as “a shriek of death.”  The sound is shocking and sent a chill up the spines of everyone who was around to hear it. It is the sound of a human scream.

The dreadful, high-pitched sound of the whistle is perhaps most comparable to a human scream. “There are different air streams generated within the structure of these instruments, which then diametrically hits against each other,” said Arnd Adje Both, a music archeologist who has examined the whistle. “And thus the Aztecs were able to produce a very shrill and noisy sound.”