Scientists Discover Sperm Whales Use Vowel Sounds Like Human Speech

Breakthrough Reveals Whale Language Complexity

Deep beneath the ocean's surface, sperm whales are having conversations that sound remarkably like human speech. Scientists have discovered two distinct patterns—an ɑ-vowel and an i-vowel, along with several diphthong-like patterns—in sperm whale communication . These calls are "more like very, very slow vowels" rather than the simple morse code-like patterns researchers previously believed .

The groundbreaking research, led by UC Berkeley linguist Gašper Beguš as part of Project CETI, analyzed nearly 4,000 whale vocalizations recorded between 2014 and 2018. When researchers sped up the recordings, they could hear new sonic qualities in the codas—sounds that resembled vowels in human speech . The team found that sperm whale codas fall into distinct categories that behave like vowel sounds in human speech, with consistent differences in length, patterns, and interactions with neighboring sounds .

These findings represent "one of the closest parallels to human phonology of any analyzed animal communication system" . The spectral properties discovered are so similar to human vowels that researchers can use human letters to describe them , suggesting an extraordinary convergence in how complex communication systems evolve.

How Whale Vowels Mirror Human Speech

The parallels between whale and human communication run deeper than simple sound similarities. Sperm whale vowels contain different lengths, with a-codas lasting significantly longer than i-codas, similar to how humans naturally make lower "a" sounds longer by opening their jaws wider . Individual whales have their own timing for how they use these codas, and neighboring sounds can influence each other, similar to compound sounds in human speech .

Sperm whales create these sounds by flapping "phonic lips" in their nose—structures akin to human vocal cords—and combine these clicks into rhythmic series called codas . The research team found more variation in i-codas, which have long and short versions, similar to how lengthening vowels in some human languages entirely changes meaning—like the difference between "wine" and "boron" in Hungarian .

Sperm whales exchange these vowels and diphthongs with each other in what resembles a dialogue . The whales' production of these sounds appears controlled and intentional across almost all individuals, though researchers don't yet understand the meaning .

Revolutionary Technology Unlocks Ocean Secrets

Scientists with Project CETI are using advanced bio-logging technology and artificial intelligence to record and analyze sperm whale communication, capturing high-fidelity audio and behavioural data . Unlike earlier whale-tagging technologies, the CETI bio-logger gathers a richer array of data and can distinguish between individual whales, enabling researchers not just to listen, but to interpret communication in context .

Researchers used generative adversarial networks (GANs), machine learning models that learn languages by listening and imitating, similar to human children . Previous MIT research with Project CETI had already expanded the known whale vocabulary from 21 different codas to more than 156 using musical analysis of tempo, rhythm, and ornamentation .

Founded in 2020, Project CETI has grown into the world's largest interspecies communication initiative, bringing together eight institutions and around 50 scientists working across artificial intelligence, linguistics, cryptography, marine biology, and robotics .

Toward Interspecies Communication

Understanding whale language could tell us whether language is unique to humans, provide insight into how language evolved, and potentially give us a way to communicate with another species on their own terms . These highly social mammals live in tight-knit clans that hunt, sleep, and raise calves together, with babies babbling for years before learning meaningful communication and different clans having distinct dialects .

Through understanding sperm whale vocalizations, Project CETI hopes to inspire the public and policymakers to push for legal protections, similar to how the 1970s "Save the Whales" movement was inspired by humpback whale songs . This research could pave the way toward rethinking the moral and legal distinctions separating humans and animals, potentially aiding both conservation efforts and the animal rights movement .

While we're still far from understanding what sperm whales are actually saying to each other, these discoveries suggest we may be closer than ever to bridging the communication gap between species. The ocean's most mysterious conversations are finally beginning to make sense.