Paul Cziko, a visiting professor at the University of Oregon and lead author of a new study, has announced the discovery of strange seal sounds.
“The call of the Weddell seal makes an almost unbelievable sound like that of another world under the ice. It really feels like you’re in the middle of a space battle in a sci-fi movie,” said the professor. Paul Cziko said.
The noise that Weddell seals produce can exceed 200 kHz.
Cziko and his colleagues were surprised after two years of listening to Weddell seals (Leptonychotes weddellii) with a special hydrophone (an underwater microphone) installed in the McMurdo Sound research station in Antarctica in 2017.
Before the recording began, scientists knew about 34 seal calls that are audible to the human ear. Recently, after a period of research, they have added 9 new types of ultrasonic calls of seals. Those sounds include hisses, whistles and cries described as… aliens, sometimes made up of different sounds mixed together.
Humans hear in the audible range of 20 to 20,000 hertz (or 20 kilohertz). Meanwhile, most of the newly discovered sounds exceed 21 kHz, with some even going up to 30 kHz continuously.
“A sound reaches 49.8 kHz when seals use multiple tones. The noise produced can exceed 200 kHz. This is far beyond the hearing capacity of cats, dogs and even some bats.” , the researchers said.
What is the mystery behind all these high frequency communications? Researchers so far have not been able to clarify.
These sounds, as Cziko explains, could just be an extra conversational element to stand out above all the lower frequency noise, like switching to another channel for communication.
Theoretically, the noises are related to echolocation, the type of biological sonar that animals like dolphins and bats use to find their way around dark places. But so far, there is no evidence that seals use echolocation.