A researcher has unravelled the mystery behind seals’ underwater “outspokenness” that leaves the human communication apparatus at the dim end of evolutionary revelations.
Many who have done diving and gaped at the sight of underwater miracles have been left puzzled that their cry of amazement, however grand it was, could be barely heard in the Neptunian abyss.
Meanwhile, seals can be heard and communicate not only in the sea but also on land, which outstrips humans — their distant mammalian cousins.
Researcher Łukasz Nowak of the Netherland’s University of Twente tackled this mind-boggling phenomenon and shared his findings saying: “grey seals are somewhat like an old married couple. They speak with one another very rarely, during mating season, to be precise, a season which for seals occurs only at the beginning of the year, right after pups are born and females are ready to get pregnant again. That is when the communication between males, females and pups becomes very lively.”
Researching how seals are capable of emitting sounds both underwater and on land could “inspire us to build systems allowing underwater communication” as Mr Nowak put it. To bring humankind closer to this Vernerian vision, the researcher examined sounds produced by grey seals at the University of Gdańsk’s seal sanctuary at the Polish coastal town of Hel.
He singled out three groups differing in terms of acoustics and presented a hypothesis on how the sounds could have been generated. It turned out that in order to pass on sound signals underwater, seals convert the vibration of air particles into the vibration of their entire bodies. This is thanks to the properties of seals’ mechanical tissues being quite similar to those of water. This is why vibrations, which is just another word for sounds, easily pass from their bodies and into the water.
“Thus seals’ bodies work like huge underwater loudspeakers,” the researcher told the Polish Press Agency (PAP), adding that the properties of seals’ vocal systems “unlike dolphins who use ultrasounds are very akin to those of humans. That is why seals inspired me to design a voice communication system for divers.”
Mr Nowak’s team designed the solution a couple of years ago. “Together with my team, we have built prototype devices for communication between divers,” said the inventor, adding that the divers spoke to their device which in turn passed the vibration on into the water, making the user capable of being heard.
Nevertheless, the voice was sealed silent because of commercial issues. “The device worked… We had a shot at commercialisation but crashed against the implementation phase. The project died,” the scientist admitted.
Although the exploits of Mr Nowak’s team were not capitalised upon, the research results remain and can be accessed at Bioacustics journal.
Source: POLAND IN