Suzanne's Mom's Blog

Photo: Minette Layne/Wikimedia Creative Commons.
Toothed whales like orcas can make astonishingly loud sounds in three vocal registers. How do they do it despite the tremendous pressure underwater?

Do you remember Rudyard Kipling’s Just So Stories? Our favorite growing up was “How the Elephant Got Its Trunk.” I still have a wonderful recording on cassette of my father reading it aloud in his stentorian voice. We loved Kipling’s robust language and used his expressions in daily life. For example, we always said that our Uncle Jim spoke just like the tale’s python rock snake, who lived “on the banks of the great grey-green, greasy Limpopo River, all set about with fever-trees.”

(Is Kipling PC these days? I hope we can take him with a grain of salt. I would hate to lose these stories.)

Hannah Devlin at the Guardian harks back to Kipling in her report on whales with voices.

“The question of how the whale got its voice has been solved by scientists, who have discovered how the creatures use ‘phonic lips’ in their nose to produce the loudest sounds in the animal kingdom.

“The research also reveals that toothed whales, a group that includes killer whales, sperm whales, dolphins and porpoises, use three vocal registers equivalent to vocal fry (a low creaky voice), a normal speaking voice and falsetto.

“The research [was presented] at the annual meeting of the American Association for the Advancement of Science (AAAS) in Washington DC. …

“Prof Peter Madsen, a whale biologist at Aarhus University in Denmark and lead author, said: ‘These animals are producing the loudest sounds of any animal on the planet while being at a depth of 1,000 metres [3,280 feet]. It just seems such a paradox.’

“A central puzzle was how whales manage to generate sufficient flow of air, given that at 1,000 metres below the surface the pressure is so great that the air in the whale’s lungs is crushed to 1% of the volume it would occupy at the surface.

“The latest work shows that as whales dive deep below the surface, their lungs collapse and air is compressed into a small muscular pouch inside the mouth. To make a click, the whale opens a valve on the pouch for about a millisecond causing a high pressure blast of air to pass through a vibrating structure in the nose, called the phonic lips.

“ ‘When the lips slap back together, that’s what makes the click,’ said Madsen. The clicks, used to navigate and hunt prey, can reach volumes equivalent to a very powerful rifle being fired.

“The study, carried out over a decade, used high-speed video recorded through endoscopes, and collected audio recordings, using electronic tags, from trained dolphins and porpoises, and sperm whales and false killer whales in the wild. The researchers approached the huge marine mammals at sea in small boats and waited for them to come close in order to attach lightweight recording devices.

“ ‘Many whales will come up to us and have a look and echo-locate on the boat,’ said Madsen. ‘I sometimes wonder who is studying who – except they don’t put a tag on us.’ The recordings revealed three distinct registers. …

“The analysis, published in the journal Science, showed the whales use two additional registers for social communication. Scientists know that toothed whales have sophisticated social communication abilities, ranging from cooperation during hunting to the signature whistle that dolphins use to identify themselves. Other species, such as killer and pilot whales, make very complex calls that are learned and passed on culturally like human dialects.”

More at the Guardian, here. No firewall. Donations solicited.