But academics from Denmark have now found that killer whales, sperm whales and porpoises make a similar sound.
Analysis of cetacean sounds has found they can make three types of sound: vocal fry, low, creaky sounds; chest register, which makes normal sounds; and falsetto.
“Vocal fry is a normal voice register that is often used in American English. Kim Kardashian, Kate Perry and Scarlett Johansson are well-known people using this register,” said study author Prof Coen Elemans, voice scientist at the Department of Biology, University of Southern Denmark.
According to the new research, toothed whales use this vocal fry register to produce their echolocation calls to help them catch prey.
‘Vocal fry made toothed whales an evolutionary success story’
“During vocal fry, the vocal folds are only open for a very short time, and therefore it takes very little breathing air to use this register,” Prof Elemans said.
“While vocal fry may be controversial in humans and may be perceived as everything from annoying to authoritative, it doubtlessly made toothed whales an evolutionary success story.”
The way the body makes the low vocal fry tone is efficient and therefore ideal for using echolocation as a food radar, the scientists believe.
“And this air economy makes it especially ideal for echolocation,” said co-author Prof Peter Madsen, whale biologist at the Department of Biology, Aarhus University in Denmark.
“During deep dives, all air is compressed to a tiny fraction of the volume on the surface.”
Echolocation is used by toothed whales when they are in a deep dive, up to 2000 metres below sea level, and make up to 700 clicks per second.
The way these clicks travel through the murky waters and bounce off prey animals can tell the whales where their next meal may be.
Forty years ago scientists thought whales made sounds with their larynx, like other mammals including people, but this was then found not to be true as they actually utilise their noses.
Using cameras down the noses of some whales, the Danish researchers learned more about how this system works.
Whales have evolved an air-driven sound system in their nose, similar to an organ, which actually works in the same way as a larynx, or voice box, but is located in the nose, not the throat.
“Evolution has moved it from the trachea into the nose, which allowed much higher driving pressures - up to five times what a trumpet player can generate - without damaging lung tissues,” said Prof Madsen.
“This high driving pressure allows toothed whales to make the loudest sounds of any animal on the planet,” Prof Elemans added.