The true purpose of these artifacts has baffled experts. Were they used to terrorize enemies in warfare? Aztec warriors were known to beat wooden drums as they advanced into battle—might they also have blown these ghastly whistles? “You can imagine the frightening sound if you had 200 or 300 or 5,000 warriors blowing these instruments,” said Jaime Arredondo, an art historian and professor of Mesoamerican and Latino studies at New York University. “That would be extremely intimidating.”