Chilling moment sound of 'death whistle' is caught on doorbell camera

Even going downstairs after dark can be hair-raising experience so going into the garden is something else entirely.

One person who was taking their dog out late at night certainly got an unpleasant surprise when a terrifying noise made both the human and the dog swiftly leg it back inside.

And when you hear the noise, you'll understand:

Footage from a doorbell camera, which was shared by a X account, shows the person standing in their backyard when a piercing, nightmarish shriek cuts through the silence.

And understandably, they legged it back indoors. As you would.

But what was this horrifying shriek?

Well, it's possible that this was produced by an Aztec Death Whistle - or least a modern reproduction of one.

According to The Daily Mail, the whistle was first discovered in the arms of a skeleton by archaeologists when excavating a Aztec temple in 1999.

What was notable was that the body was clutching a pair of skull-shaped instruments in each hand - possibly in reference to Mictlantecuhtli, who is the Aztec god of the underworld.

Getty stock image

In a YouTube video about the whistle, James J. Orgill, who tested a 3-D printed whistle, said the archeologists initially dismissed it as 'some sort of toy'.

Adding: "It wasn't until 15 years later for some reason a scientist blew into the hole in the top of it and this is the sound that came out."

Since their discovery, there has been a common misconception that the whistles were used to create the terrifying shriek in order to frighten enemies.

But the truth is that we don't actually know exactly how or why the Aztecs used these whistles.

According to HowStuffWorks, music archaeologist Arnd Adje Both investigated the unusual instruments, taking CT scans of the original whistles and replicating the structures as closely as possible.

And the resulting sound?

It's far softer than the screech produced by larger modern replicas.

Avalon/Universal Images Group via Getty Images

Both suggested that the whistles, which he describes as 'air spring' instrument, may have been used as a way to symbolically guide someone to the afterlife as the god of wind was often connected to the god of the underworld.

But what about the myth that Aztecs terrified their enemies by sounding the whistles?

Well, an account from Tomás de Torquemada, a Spanish friar, described an Aztec general as carrying 'a drum on his shoulders which he played at the start of a battle while others blew large shell trumpets'.

But Both says that theory is still just a 'possibility'.

"Up to this point, we haven't excavated an individual classified as an Aztec warrior with such an instrument around their neck." he said.

"For now, it seems to be more of a ritual instrument."

And as for the shrieking on the camera, some suggested that it could just be an animal, like a mountain lion or fox.