Researchers find Aztec 'death whistles' do weird things to the listeners' brains

Recent research of the sounds of ancient Aztec skull-shaped whistles revealed their profound psychoacoustic effects on modern listeners. For the first time, scientists have examined the impact of these disturbing whistles on the brains of modern European volunteers, including two separate experiments with different samples of participants. The study was published in the journal Communications Psychology.

The skull-shaped whistles were designed to produce a high-pitched, penetrating sound similar to a scream, resulting from the collision of different air currents. They are commonly known as "death whistles."

Numerous Aztec skull-shaped whistles have been found in tombs dating from the period between 1250 and 1521 AD, with many preserved in archaeological collections worldwide. It is presumed that the ancient Aztecs used the death whistles in war to terrorize enemies on the battlefield. Death whistles are regularly found alongside the skeletons of sacrifice victims. The frequent presence of death whistles next to the bones of sacrificial victims has led to the hypothesis that they may have had a ceremonial function, particularly in sacrificial rites and ceremonies related to the dead.

Some scholars believe that the death whistles were intended to emulate the sharp winds of Mictlan, the Aztec underworld, where it was believed the souls of the sacrifices descended. Other scholars hypothesize that the sound of the whistles could represent Ehecatl, the Aztec God of Wind, who, according to legend, created humanity from the bones of the deceased. It is hypothesized that the skull-shaped whistles could have been employed to frighten participants in human sacrifices or ritual ceremonies, as they might have been used to scare the human sacrifice or the ceremonial audience.

The researchers recorded participants' neural and psychological responses to hearing the death scream produced by these whistles. Through the use of various neuroimaging techniques, they identified specific brain activity in low-level cortical auditory regions. The sound of skull whistles puts the auditory cortex on high alert.

Participants defined the sounds of the skull-shaped whistles primarily as extremely negative, frightening and aversive. The researchers noted the sounds potentially interfere with ongoing mental processes. The researchers detected a difficulty in the brain to classify the sound, which ignites the imagination as the brain struggles to pinpoint its symbolic meaning.

The sounds of the skull-shaped whistles have been shown to attract mental attention by affectively mimicking other aversive and startling sounds produced by nature and technology. The sound was perceived as "having a hybrid natural-artificial origin."

The authors of the study conclude that the use of the whistles in ritual contexts, especially in sacrificial rites and funeral ceremonies, is very likely.

This article was written in collaboration with generative AI company Alchemiq