But in the forests of central Mexico, a single note from an Aztec whistle didn’t always indicate celebration — it meant death. “Death whistles,” or Aztec skull whistles, were short, carved instruments ...

When archaeologists blew into these creepy kazoos, they emitted an unearthly, banshee-like shriek similar to a haunted ...

Brain scans of modern listeners suggest that Aztec whistles sound like human screams, which may have prepared sacrifice ...