'Most terrifying sound in the world' that was last thing people heard before death has shocking effect on your brain

Research into the sound created by an ancient Mesoamerican civilisation has revealed the disturbing impact it has on the brain.

Anyone who's familiar with history won't need reminding that our ancestors could be downright creepy at times.

From harrowing execution methods such as the brazen bull, the fabled blood eagle and medieval oubliettes, to sadistic torture methods and sacrificial killings. All I can say is that people had a lot of time on their hands in the days before the internet.

And, thanks to dedicated teams of historians and archeologists around the world, we're constantly learning more and more about the wonderful and downright grisly habits of our ancestors.

This includes the rather ominously named Aztec 'death whistle', which has captured imaginations due to its macabre connotations.

A replica of the Aztec 'death whistle' (Getty Stock Images)

What is the Aztec 'death whistle'?

Uncovered during the excavation of a temple at Tlatelolco in Mexico City during the 1990s, archeologists found the remains of a male sacrificial victim alongside numerous musical instruments.

Included in the findings was a small, skull-shaped whistle, which promptly earned the name of 'death whistle' due to its proximity to the remains of a sacrificial victim.

According to howstuffworks, the whistle is a rather unique 'air spring' instrument and is believed to have been used in ceremonial situations, such as a ritual sacrifice. The inner workings of the instrument was investigated by music archeologist Arnd Adje Both, who explained to the outlet the whistling sound was down to an internal chamber which distorted the sound.

The skull is also thought to represent Mictlantecuhtli, the Aztec god of death and the underworld.

Researchers have blown recreations of the death whistles (Tanner Pearson/The Boston Globe via Getty Images)

What impact does the Aztec 'death whistle' have on the brain?

Given the fact that these instruments have the name 'death whistle', it's understandable to associate using one with summoning impending doom, either on yourself or everyone around you.

Reconstructions of the whistles have since been blown by researchers, thankfully causing nothing terrible to happen. However it would appear the whistles have an rather morbid impact on the brain.

A study was conducted by the University of Zurich last year, with the whistle being played to group volunteers.

Take a listen of what it sounds like below:

And what they heard, they didn't like.

The 70 participants overwhelmingly associated the sound with negative emotions as well as 'natural' sounds such as animal screams.

An additional study on 32 volunteers using an fMRI scan revealed the whistle activated an area of the brain which is associated with symbolic meaning.

"This is consistent with the tradition of many ancient cultures to capture natural sounds in musical instruments, and could explain the ritual dimension of the death whistle sound for mimicking mythological entities," lead author Sascha Frühholz said in statement.

Which more than likely explains why the unfortunate soul who appeared to hear the whistle in this clip while out in the garden with their dog absolutely booked it inside.