Anything’s spooky if you hype it up right (creaking doors, echoing footsteps, wind), and I’m sure this would be an upsetting sound to hear if you knew it heralded nearby killer Aztecs, but in itself… ehh.
It is interesting, though, to imagine the headspace of pre-electronic media environments where the only way to hear an unfamiliar sound was in the physical presence of the specific, esoteric thing that made that sound. Idiophone construction is an obscure skill even today, so you can imagine whistles and bells being imbued with magical qualities.
This reminds me of Whistle and I’ll Come to You:
But even more so of The Shout, a strange 1978 movie where John Hurt meets a stranger who claims to have learned an Australian Aboriginal “terror shout” that will kill anyone in earshot. (Spoiler: yes, you do hear the sound in the movie, kind of)
