Scientists have long known that sperm whales use powerful clicking sounds to communicate using rules similar to those in human speech. To human ears, these clicks often sound like simple, repetitive taps.
The study was led by researchers at Project CETI and published in Proceedings of the Royal Society B: Biological Sciences. It provides fresh evidence that whale communication is more structured than previously understood.
Large dataset reveals hidden structure
Researchers analyzed nearly 4,000 click sequences, known as codas, from recordings collected off the coast of Dominica. The study focused on 15 young female whales. Mature males were excluded because they usually live alone and show different communication patterns.
The team examined the shape of each sound wave. They looked at frequency peaks and measured the timing between individual clicks. This approach allowed them to uncover consistent patterns within the codas.
Distinct sound types and timing patterns
The study identified two main types of codas based on their acoustic features. Researchers labeled them “a-codas,” which have one frequency peak, and “i-codas,” which have two. A-codas are generally longer, while i-codas can appear in both shorter and longer forms.
Sperm whales may be speaking in ways more similar to humans than we thought.
A new study finds their clicks follow structured rules, with patterns, timing, and overlap—just like human speech. pic.twitter.com/xEvKKQ9EIW
— Tom Marvolo Riddle (@tom_riddle2025) April 16, 2026
Scientists also found that individual whales have unique timing styles. Some produce clicks in rapid sequences, while others space them out more slowly. These differences resemble variations in how humans speak.
Overlapping sounds mirror human language
Researchers observed that when whales move from one coda to another, the first click of the new sequence can reflect features of the surrounding sounds. This overlap is similar to patterns in human speech, where sounds influence one another depending on their position within a word.
By combining these features, sperm whales can produce thousands of different click patterns. This flexibility suggests a communication system with a high level of organization.
Independent evolution of similar systems
Despite the similarities, researchers say whale communication did not evolve from human language. Instead, both systems likely developed similar features independently. This process, known as convergent evolution, occurs when different species develop comparable traits to solve similar challenges.
Implications for understanding whale communication
The findings could help scientists move closer to decoding whale communication. Sperm whales rely on sound to stay connected in the deep ocean, where visibility is limited. A better understanding of their vocal patterns may reveal how they share information and maintain social bonds.
Researchers say more work is needed before these sounds can be fully understood. Still, the study marks an important step toward uncovering how these animals communicate using patterns that closely resemble the rules of human speech.
