Above the water they sound like dragging Vuki. Under the ice they sound like chirping, chattering robots. In any case, Weddell seals from Antarctica should have no problem finding a job in the coming period Star Wars project.
“Weddell seal calls create an almost amazing, otherworldly sonic landscape under 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 sounds like you’re in the middle of a space battle in Star Wars, laser beams and all. “
The catch: You would have to be an alien (or droid) to hear them; all these sci-fi sounds are completely inaudible to human ears.
Cziko and his colleagues were able to detect otherworldly sounds after two years of listening to Weddell’s seals (Leptonychotes weddellii) with a special hydrophone (underwater microphone) installed in Antarctic McMurdo Sound in 2017.
Before researchers began filming, scientists knew of 34 seal calls heard in human ears. The team’s research is now – published online on December 18 Journal of the American Acoustic Society – adds nine new types of ultrasonic calls to the seal repertoire. These sounds include triceps, whistles, and the chirping of an alien sound, sometimes composed of more harmonized tones.
Researchers have observed that people hear in the sound range of 20 to 20,000 hertz (or 20 kilohertz). Most of the newly discovered seal sounds exceeded 21 kHz, and some have steadily climbed to 30 kHz.
Above: 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 a call of type U101.
One high-pitched whistle reached a screaming 49.8 kHz, the team wrote – and when the seals matched multiple tones, the resulting noise could exceed 200 kHz. (This is far beyond the hearing range of cats, dogs and even some bats.)
What are all these high-frequency communications about? Researchers are unsure; so far scientists have never discovered ultrasonic vocalizations on seals (or on any other mammal with a foot, such as sea lions or walruses).
According to Czik, sounds could only be additional elements of conversation that “stand out above all lower frequencies of noise, such as a change to another communication channel.”
It is theoretically possible that noise is involved in echolocation, a biological sonar that animals like dolphins and bats use to navigate dark places. But so far there is no evidence that seals use echolocation, the researchers said.
However, the behavior of seals that can dive more than 1,900 feet (600 meters) underwater and hunt in the darkness of the Antarctic winter would not be characteristic, the team added.
Let’s see how Wookie tries to do that.
This article was originally published by Live Science. Read the original article here.