Killer whales catch prey by sounding like Kim Kardashian 

By Mark Waghorn via SWNS

Killer whales catch prey by communicating in husky tones that resemble the voices of Kim Kardashian, Paris Hilton and Julia Fox.

Known as "vocal fry," in humans, it produces the lowest sounds by dragging out syllables.

Now the phenomenon has been identified in orcas and dolphins who use a similar technique for echolocation during hunting.

Lead author Professor Cien Elemans, of the University of Southern Denmark, said: "Vocal fry is a normal voice register that is often used in American English. Kim Kardashian, Katy Perry and Scarlet Johannsen are well-known people using this register."

The drawl is a common way of speaking in California. It has been picked up across the world thanks to the popularity of American media.

Britney Spears fuelled the craze by using it in her pronunciation of her debut hit "... Baby One More Time."

Whales and dolphins are intelligent apex predators that capture our imagination. They can cooperate - following prey more than a mile beneath the waves in complete darkness.

They rely on sound but their rich vocal repertoire has remained mysterious.

The study in the journal Science identified an air-driven nasal source that operates at different levels - just like the human voice.

Prof. Elemans said: "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."

The two others are the chest, our normal speaking voice, and falsetto, which produces even higher frequencies.

Toothed whales dive as deep as 2,000 meters, catching more fish than the fishing industry. They produce short, powerful, ultrasonic echolocation clicks at rates up to 700 per second to locate, track and catch prey.

Co-author Prof. Peter Madsen, of Aarhus University, explained: "This air-economy makes it especially ideal for echolocation.

"During deep dives, all air is compressed to a tiny fraction of the volume on the surface.

“Thus vocal fry allows whales access to the richest food niches on earth; the deep ocean."

Experts have suggested women use it to seem more masculine and better equipped to take on men in the workplace.

Others have described it as potentially 'vocally damaging'. It can cause laryngeal tension and vocal fatigue.

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."

It was previously thought they make sounds with their larynx just as other mammals. But 40 years ago it became clear that this is not the case.

They somehow use their nose to produce sound. The Danish team uncovered what exactly goes on using high-speed camera tubes.

Images showed toothed whales have an air-driven sound production system in their nose.

It functions in a similar way to sound production in mammals and birds – but its location is far from the same.

Prof. Madsen said: "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."

At depths over 100 m, whale lungs collapse to avoid compression sickness and are thus no good for air supply.

The remaining air is found in the nasal passages of the skull. This provides a small, but sufficient airspace to produce echolocating sound at astonishing depths.

Prof Elemans said: "This high driving pressure allows toothed whales to make the loudest sounds of any animal on the planet."

When echolocating, toothed whales pressurise air in their bony nose and let it pass structures called phonic lips that vibrate just as human vocal folds.

Their acceleration produces sound waves that travel through the skull to the front of the head.

In addition to echolocation, toothed whales make a huge array of sounds for their complex social communication.

Prof. Madsen said: "Some species, like killer and pilot whales, make very complex calls that are learned and passed on culturally like human dialects."

The study showed sounds are made by the phonic lips vibrating in the chest and falsetto registers.

The researchers filmed the phonic lips using both trained dolphins and animals in the wild that were moving freely with a small tag that recorded their sounds.

Videos were filmed at Dolfinarium Harderwijk in the Netherlands, Europe's largest marine mammal park.

Prof. Elemans added: "It took us close to 10 years to develop new techniques, gather and analyse all our data."