One of the most interesting but terrifying religious practices of Aztec culture was the Aztec death whistle. The skull-shaped ceramic instrument not only looks creepy—it also produces the most horrifying noise in history.
Many people have compared the sound of the death whistle, originally known as the ehecachichtli, to the howl of the wind or the “wail of a thousand souls.”
The whistles are highly effective at instilling fear into the hearts of those who heard them, but it has always been unclear why that is. Researchers finally have an answer as to why the sound of the whistles is so scary.
Aztec death whistles, or skull whistles, are small clay creations from ancient Mesoamerica, particularly the Aztec civilization. The first ones were discovered by researchers in 1999.
Since then, a number of skull whistles have been recovered from Aztec sites. Most were found in the burials of sacrifice victims.
When the whistles are blown, they emit an eerie, high-pitched noise that sends chills down the spine. It resembles both a howling wind and a human shriek.
The whistle’s internal structure creates air turbulence to produce the frightening sound. Scholars have long debated over the purpose of the whistles.
Some have suggested that they were used in sacrificial ceremonies to guide souls to the afterlife. The noise may have also represented the Aztec wind god Ehecatl or the god of death, Mictlantecuhtli.
There have also been claims that the whistles were used during warfare to strike fear into the enemy, but little evidence exists to support the idea. No whistles have been found in battle sites or in the graves of warriors.
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So, researchers decided to conduct a study to investigate the effects of Aztec death whistles. To determine how the human brain responds to the sound, they recruited 70 volunteers for psychoacoustic testing.
In addition, 32 of the participants had their brains scanned while they listened to the death whistles among a randomized selection of sounds from five different categories.
The researchers found that the sounds produced by the death whistle have both a natural and artificial origin, which is what makes them so terrifying.
The strange mix makes it difficult for human brains to classify where the sound is coming from. It’s unsettling and seems almost human, but not quite.
“Human listeners in our experiments rated skull whistle sounds as very negative and specifically labeled them largely as scary and aversive, which potentially also trigger urgent response tendencies and interfere with ongoing mental processes,” wrote the researchers.
“This immediacy effect is further highlighted by very specific brain activity in low-order [auditory cortical regions] that is correlated with the affective similarity of [skull whistles] to other sounds.”
It is likely that the death whistles were used in sacrificial rituals and burial ceremonies due to their association with Aztec deities. They have a symbolic nature related to the dead and the underworld.
There is still a lot to uncover about the Aztec death whistle, but it is interesting to see its psychological connection.
The research was published in Communications Psychology.
