A new study led by the University of California, Berkeley’s Linguistics Department and Project CETI (Cetacean Translation Initiative) suggests that sperm whale communication shares notable similarities with human language. The research reveals that the acoustic properties of whale calls are similar to vowels, which are a key feature in human speech.
“In the past, researchers thought of whale communication as a kind of morse code,” said Professor Gašper Beguš, 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, titled “Vowel- and Diphthong-like Spectral Patterns in Sperm Whale Codas,” identified two main patterns resembling the ɑ-vowel and i-vowel found in human languages. Several diphthong-like patterns were also discovered in the whales’ vocalizations. According to Beguš, sperm whales appear to exchange these vowel and diphthong sounds with each other in ways similar to 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 explore how sperm whales communicate.
Beguš noted that whale vowels display many characteristics seen in human vowels such as differences in length, timing, frequency and trajectory. These elements carry meaning in human speech; it remains possible they serve a similar purpose for sperm whales.
“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 findings represent progress toward decoding sperm whale communication but may also have broader implications beyond translation efforts. As Beguš explained: “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?”
According to Project CETI researchers, challenging previous assumptions about animal communication could prompt reconsideration of moral and legal boundaries between humans and animals. Beguš believes understanding whale communication could benefit both conservation work and animal rights advocacy.
Project CETI aims ultimately to translate sperm whale communications into understandable forms for humans. Over five years of observation using tags on animals as well as buoys and aquatic or aerial drones has helped researchers learn more about how these mammals interact vocally.
To examine acoustic patterns within whale calls more precisely than before—when studies focused mostly on clicks—Beguš used generative adversarial networks (GANs). These machine learning models detect complex structures within large datasets by mimicking how children learn languages through listening and 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.”
By applying GANs alongside traditional linguistic analysis methods—which included examining vowel combinations known as diphthongs—the team was able to reveal greater complexity than earlier research had shown when focusing only on click types or timing between clicks.
“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 this approach is helping reshape both linguistics itself and our understanding of life: “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.”
