Above the water, it sounds like a shouting Wookie. Under the ice, they sound like talking, talking robots. Either way, Weddell seals in Antarctica should have no trouble finding work in the future Star Wars project.
“The calls of Weddell seals create an almost incredible soundscape in other worlds under the ice,” said Paul Cziko, a visiting professor at the University of Oregon and lead author of a new study describing the bizarre sounds of seals. “It really seems like you’re in the middle of a space battle Star Wars, laser beams and all that. “
Capture: You should be an alien (or a droid) to hear them; all these SF sounds are totally inaudible to human ears.
Cziko and his colleagues were able to detect the noises of the world after two years of listening to Weddell seals (Leptonychotes weddellii) with a special hydrophone (an underwater microphone) installed in McMurdo Sound in Antarctica in 2017.
Before researchers began recording, scientists knew about the 34 audible seal calls to human ears. Now the team ‘s research – published online on December 18 in Journal of the Acoustic Society of America – adds nine new types of ultrasonic calls to the seal repertoire. These sounds include trills, whistles and chirps with extraterrestrial sounds, sometimes composed of several harmonized tones.
People hear in the sound range of 20 to 20,000 hertz (or 20 kilohertz), the researchers noted. Most newly sealed sounds exceeded 21 kHz, some constantly increasing to 30 kHz.
(McMurdo Oceanographic Observatory)
Above: A visual representation (spectrogram) of one of the nine types of ultrasound calls. The U-shaped features in the upper half of the plot are part of the U101 call type.
A loud whistle sounded 49.8 kHz, the team wrote – and when the seals harmonized more tones, the resulting noise could exceed 200 kHz. (It goes far beyond the hearing range of cats, dogs and even bats.)
What are all these high frequency communications about? Researchers are not sure; Until now, scientists had never detected ultrasound vocalizations in seals (nor in other mammals with swimming legs, such as sea lions or walruses).
A diver from the McMurdo sound of Antarctica notices a Weddell seal. (McMurdo Oceanographic Observatory)
According to Cziko, the sounds could be just bonus conversational elements to “highlight lower frequency noise everywhere, such as switching to a different channel for communication.”
Theoretically, it is possible that noises are involved in echolocation, the biological sonar that animals such as dolphins and bats use to find their way around dark places. But so far, there is no evidence that seals use echolocation, the researchers said.
However, the behavior would not be without character for seals that can dive more than 600 meters under water and hunt in the dark winter of Antarctica, the team added.
Let’s see a Wookie trying to do this.
This article was originally published by Live Science. Read the original article here.