When toothed whales such as sperm whales dive to a depth of more than 1,000 meters, they are exposed to very high pressure.
The high pressure causes the whales' lungs to collapse and the volume of air they carry when diving is reduced to one percent of what it is at the water's surface.
Despite barely having any air in their lungs, toothed whales still manage to produce some of the loudest sounds in the animal world.
- They produce short clicking sounds that radiate forward in a narrow beam, perhaps hitting a fish and then bouncing back as an echo.
They interpret these echoes and if it is an edible fish, they hunt for it, says zoologist Mats Amundin, who has read the study.
Croaks and sings in falsetto
Now a group of German and Danish scientists have solved the mystery of how toothed whales manage to produce this clicking sound with very little air in their lungs.
- They found that extremely little air is needed to make clicking sounds like this.
That is one of the explanations why the whales have developed this mechanism, says zoologist Mats Amundin.
The researchers also discovered that toothed whales, like humans, have several different vocal registers when they make sounds.
The clicking sounds correspond to the creaking sounds reminiscent of Britney Spears and many other famous artists' creaky vocals.
When the toothed whales communicate with each other, they make a cracking sound similar to our song.
Toothed whales such as dolphins and the orca can also whistle, which is equivalent to when a singer sings in falsetto.
The loudest sound in the animal world
The sounds of toothed whales can be very powerful, and the clicking sounds of sperm whales are among the loudest in the animal world.
The pain threshold for human hearing is 120 decibels, but the sperm whale hisses much louder.
- If someone doesn't want to stay away, the sperm whale can just point its sound cannon at the other person's ear and it burns at 236 decibels, and it stings.