Eerie audio captures shark sounds for first known time leaving scientists stunned

Ever wondered what a shark sounds like? And no, it’s not duh-nuh, duh-nuh, nuh nuh nuh nuh nuh nuh etc.

Sharks are thought to be the silent and deadly type, so much so that when a scientist started hearing strange noises while studying them, she assumed the sounds must be something else.

Marine biologist Carolin Nieder was focusing on the marine predators as part of her PhD at the University of Auckland in New Zealand.

She was interested in how well sharks can hear, but didn’t expect them to start making noises themselves.

But she heard something very odd indeed when making recordings of rig sharks - one of the slightly less scary species that grow up to three foot three inches.

Sharks aren't traditionally known for being vocal (Getty Stock Image)

They have flattened teeth and tend to munch on animals on the seafloor like crabs rather than unfortunate swimmers.

Nieder told Scientific American: “At first we had no idea what it was because sharks were not supposed to make any sounds.

“I remember coming home and just thinking more and more about how weird those sounds were.”

You can have a listen to what she heard here:

As you can hear, it’s a strange clicking sound you definitely wouldn’t expect a shark to make.

As Nieder started to grow suspicious that it was in fact the rig sharks making the noises, she decided to test her theory by placing 10 juvenile rig sharks in a tank with sound recorders one at a time.

That’s when Nieder discovered something else peculiar - there were a lot more clicks in the first 10 seconds after the sharks had been handled by the scientists than in the 10 seconds afterwards, leading her to theorise the noises were the sharks’ response to being startled.

The study found the sharks produced an average of nine clicks over the course of 20 seconds in the tank, with each click lasting 48 milliseconds.

It gradually dawned on her she had something pretty big on her hands - the first ever recording of noises made by a shark.

Carolin Nieder was shocked by the discovery (ABC News)

As to why they are making this noise, Nieder told ABC News: “The rig is a smaller shark. It's vulnerable to predation.

“Maybe if a small shark like this gets attacked, maybe these clicks can disorient the predator for just a split second to escape.”

How do they make the noise? Writing in a study published last week, Nieder and the other researchers conclude: “We propose that forceful snapping of flattened teeth may be the sound producing mechanism based on the plated tooth morphology and the acoustic characteristics of these clicks.

“Further behavioural studies are needed to test whether clicks are incidental to the handling or a natural acoustic response of behavioural significance.”