Sperm Whales Have Using Something Like Vowels for a Very Long Time

Sperm whales don't just make sounds that acoustically resemble human vowels. They use those sounds the way we do.

A 2026 study from Project CETI and UC Berkeley, published in Proceedings of the Royal Society B, analyzed nearly 4,000 click sequences, called codas, from 15 female and immature Caribbean sperm whales recorded between 2014 and 2018. What researchers discovered wasn't just a resemblance to human speech, it was a structural parallel to human phonology across five separate dimensions.

Sperm whale codas break into two vowel-like types: a-codas (one acoustic peak) and i-codas (two peaks). These aren't random. The two types show up in predictable patterns depending on which coda rhythm is being used, a parallel to how vowel quality and tone interact in languages like Mandarin. A-codas run longer than i-codas on average, mirroring the cross-linguistic tendency for open vowels to take more time than closed ones. I-codas come in short and long versions, the way languages like Hungarian use vowel length to distinguish meaning. Individual whales even have their own baseline timing, their own pace, the way different people speak fast or slow. And when a whale shifts from one vowel type to the next, the first click of the new coda sometimes still carries a trace of the previous one, a phenomenon linguists call coarticulation.

None of this meaning has been decoded yet. The researchers are careful to call it a communication system, not a language. What they will say is that it's probably the most phonologically complex animal communication system ever analyzed.

Whales evolved their own vowels. Entirely independently. Separately from us.

Read the full story at Oceanographic, April 16, 2026.

Hot Take: Two species, both with big brains and tight social bonds, both landed on vowel-like systems by complete accident, which says something about what kind of complexity a sufficiently social mind tends to reach for, and we've only just started listening.