Deep beneath the ocean’s surface, sperm whales may be hiding a surprising secret: their clicks and calls could resemble human speech. New research shows that some whale vocalisations include vowel-like sounds, much like the vowels we use in human language.
Gašper Beguš, linguistics lead at Project CETI, told Popular Science:
“What used to be conceived of as this alien-looking Morse-code like system just became much more human-like. We have a case of underwater vowels — in a very different world from ours, the communication system appears very similar to our speech.”
Researchers identified two distinct “coda‑vowels” in sperm whale calls, which are roughly similar to the human vowels “a” and “i.” They also discovered that whales can vary these sounds — some are long, some are short, and some rise or fall in pitch. The team even found “diphthong-like” calls, where one vowel-like sound glides into another, similar to the “oi” in the word “coin.”
Remarkably, the way whales produce these sounds is not as different from humans as you might think. Humans use our vocal folds to make vowels, while whales use structures called “phonic lips” and air sacs. These move more slowly, but when researchers sped up the recordings, the whale sounds lined up with human vowel frequencies.
Sperm whale communication clicks
David Gruber, president of Project CETI, said:
“This elucidation of sperm whale vowel and diphthongs … now showcases the sperm whale communication system [as] one of the most sophisticated systems seen across the animal kingdom.”
Shane Gero, Project CETI’s biology lead, added:
“From a biological perspective, … these findings show us that sperm whales are actively modulating sound in structured and repeatable ways. This suggests the possibility of transmitting nuanced layers of information essential to their social lives.”
If whales are using something that resembles vowels and diphthongs, it suggests their “language” could be far more complex than previously thought. These clicks and calls may not be random; they could be a structured form of communication, potentially sharing detailed information.
Scientists are only beginning to decode what these sounds mean, but one thing is clear: sperm whales may be speaking a language, and we’re finally starting to listen.
