Musical instruments were used by many ancient cultures for certain social settings and also for rituals. In the case of the Aztec culture, there is a whistle, nicknamed the ‘whistle of death’whose appearance – they are shaped like a skull – and sound have been described as creepy. A team of neuroscientists from the University of Zurich has now studied the neural and psychological responses that the shocking sound of these whistles produces in the brain.
The research, published in the journal Communication Psychologyconsisted of making psychoacoustic tests to a group of 70 volunteers around a random selection of sounds, which included the whistles coming from these skulls. At the same time, 32 of these participants were also scanned the brain while they heard, among other sounds, the ‘whistles of death’.
“Skull whistles can produce softer, hiss-like sounds, but they can also produce sounds similar to screams that were potentially significant for the sacrifices, mythological symbolism or intimidation warfare of the Aztecs,” the scientists point out in their study.
As they explain, these sounds were perceived by people as “aversive and terrifyingand as of hybrid natural-artificial origin”.
This strange mix between the natural and the artificial makes it difficult, according to researchers, for our brain to categorize the disturbing effect of sounds like these. To the not being able to classify a sound to be able to assess whether it is pleasant to us, ambiguity causes bewilderment in people.
This is what happened to the volunteers who heard the ‘whistle of death’. Hearing the sound, the lights were activated. lower-order auditory cortical regions of the brain, which are those that tune in to aversive sounds, such as screams or a baby’s cry, and direct the brain to analyze these stimuli at a deeper level.
If you compare this sound with others produced by humans and animals, musical sounds or some of nature, the skull whistle activated the inferior frontal cortexwhich is the one that deals with the elaborate classification processing, and the medial frontal cortexa region involved in associative processing. That is why the ‘death whistles’ were classified by the volunteers as a group of sounds, close to those considered alarming, such as horns, sirens or firearms, but also to other human noises that imply fear. , pain, anger or sad voices.
Many of these whistles were located in tombs dating between 1250 and 1521 AD, and some were associated with burial rituals, which has led the team of researchers to think that these whistles may have been designed to symbolize Ehécatlthe Aztec deity of the wind.
For scientists, the chilling sound coming from a skull-shaped whistle may have represented the strong winds from Mictlanthe underworld of the Aztecs.
“Taking into account the aversive/frightening and associative/symbolic nature of soundas well as currently known excavation locations at ritual burial sites with human sacrifices, their use in ritual contexts seems very likely, especially in rrituals and sacrificial ceremonies related to the dead,” the authors conclude.