Eavesdropping On Sperm Whales Just Revealed They Use Vowel Sounds "Thought To Be Unique To Humans"

You might’ve heard we’re trying to talk to whales. It sounds crazy, but it’s not so far-fetched, as in recent years we’ve been getting closer and closer to cracking the code of their remarkably complex communications.

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Now, a groundbreaking discovery has been made through eavesdropping on the conversations of sperm whales (Physeter macrocephalus). It turns out they use single and double vowel sounds in their vocalizations, sort of like how we might say “did” or “died”. Combining vowels like that is called a diphthong, and the existence of a comparative feature in whale communications has the potential to upend what we thought we knew about non-human intelligence.

"This discovery opens an entirely new chapter in our understanding of sperm whale communication,” said David Gruber, Founder and President of Project CETI, in a statement emailed to IFLScience. “By integrating linguistics and non-human communication, we are now aware that sperm whales have vowel- and diphthong-like structures in their voices, and that they evolved an entirely independent way of producing vowels.”

Studying "animal language"

Studying animal communications is very difficult for a human as, despite our best scientific efforts, we can’t help but approach it with the biases of Homo sapiens communication. A key moment for Project CETI – the organization that’s leading the charge in decoding whale vocalizations – was finding a way to move these biases to one side.

One such bias centers around timing, as our speech is created through vocal folds that vibrate much faster than the phonic lips used by cetaceans. So, if we’re going to get to grips with their "language" (we don't yet know if animals have language, FYI), we need to slow things down a bit.

Sperm whale vocalizations

Once that difference in timing was accounted for, the CETI scientists noticed something amazing: there were patterns so clear within sperm whale vocalizations that they could be transcribed using human letters (perhaps Dory’s attempt at speaking Whale wasn’t so ridiculous after all). These vowel-like sounds were clicks accented through modulation of their frequency with “a” and “i” sounds.

Those sounds could also be combined to create a diphthong-like vocal feature. That they were doing this in a structured and repeatable way suggests that these nuanced adjustments to their codas are crucial to getting their point across.

The evolution of linguistic patterns

This pivotal discovery demonstrates that the communications of sperm whales are much more intricate than we previously thought, and share more in common with our own way of speaking than we realized. It could also lead to a greater understanding of how these structural elements of speech evolved in animals, human or otherwise.

"What’s interesting from a linguistics standpoint is the resemblance to human vowel systems,” added Gašper Beguš, Project CETI’s Linguistics Lead. “The presence of consistent vowel- and diphthong-like patterns points to a level of phonetic complexity previously thought to be unique to humans. This is a step toward understanding whether the building blocks of language are more universal across species than we believed.”

The study is published in the journal Open Mind.