A new study by the University of California, Berkeley’s Linguistics Department and Project CETI (Cetacean Translation Initiative) suggests that sperm whale communication shares similarities with human language. The research, led by Professor Gašper Beguš, analyzed the acoustic properties of whale calls and found that they resemble vowels—a fundamental aspect of human speech.
“In the past, researchers thought of whale communication as a kind of morse code,” said Beguš, who is also the linguistics lead at Project CETI. “However, this paper shows that their calls are more like very, very slow vowels. This suggests a complexity that approaches human language.”
The study identified two main patterns in sperm whale sounds—an ɑ-vowel and an i-vowel—as well as several diphthong-like combinations. According to Beguš, these sounds appear to be exchanged between whales in what may function as a form of dialogue.
“The whales’ production of the ɑ-vowel, i-vowel and diphthongs is likely controlled,” Beguš said. “This is true across almost all whales. We don’t understand the meaning yet, but we know that whales produce these sounds intentionally and we know that they differentiate between them.”
Project CETI brings together experts from artificial intelligence, marine biology, cryptography, robotics and underwater acoustics to better understand how sperm whales communicate. The team has spent five years observing whale behaviors using tags, buoys and drones to collect data on their vocalizations.
Beguš explained that sperm whale vowels share key features with those in human speech: length, timing, frequency and trajectory. In humans, such features carry meaning; it is possible this holds true for whales as well.
“The spectral properties we discovered are very similar to human vowels. They correspond so closely that we can use human letters to describe them,” Beguš said. “Even the production of those sounds, which mirrors human vocal tract pulses, is similar to humans.”
The implications extend beyond translation efforts. As Beguš noted: “We’re thinking deeply about what finding these human-like structures means for the legal rights of animals. This paper prompts questions like, for example, what is language? Is there anything uniquely human about language or is it just a continuum? What does that mean for the law?”
Project CETI believes their findings could prompt a reevaluation of ethical and legal boundaries between humans and other animals while supporting conservation initiatives.
To analyze whale calls further than previous studies—which mostly focused on click patterns—the researchers used generative adversarial networks (GANs), an artificial intelligence model capable of identifying complex patterns in large datasets by learning through imitation.
“GANs can discover words and meaningful structure. When designing the model, we asked whether they could do that in whales as well,” Beguš said. “We still need human researchers to analyze the details but they help us look in a specific direction.”
The application of GANs allowed linguists to identify not only clicks but also vowel-like sounds among sperm whales—a development which adds complexity compared with earlier focus solely on click sequences.
“Before, researchers focused primarily on whale clicks and inter-click timing,” said Beguš. “Analyzing vowels adds a completely new dimension that brings much more complexity.”
Beguš added that this research represents a shift within linguistics itself: “This work is so important because it helps you relativize your own position as a human,” he said. “We exchange inner worlds through speech—through vowels and consonants. This is a small step towards understanding the inner worlds of animals—their cultures and their intelligences.”
