Sperm Whales May Have Their Own ‘Phonetic Alphabet,’ Scientists Discover

 

Scientists are getting closer to answering one of the ocean’s most intriguing questions: What are sperm whales saying to one another?

A growing body of research suggests that sperm whales communicate using a surprisingly sophisticated system of clicks that may have some striking similarities to the way humans build language.

Researchers studying the animals have identified what they describe as a “sperm whale phonetic alphabet” — a system in which different rhythms, tempos and subtle changes in their clicking patterns can be combined to create a large variety of distinct sounds.

The discovery is changing scientists’ understanding of how complex animal communication can be.

A language made of clicks

Sperm whales communicate using sequences of rapid clicks known as codas.

For years, researchers knew that these codas carried information, including clues about the identity and social group of individual whales. But scientists increasingly realised that the sounds contained far more variation than previously understood.

In a landmark 2024 study, researchers from MIT, Project CETI and other institutions analysed 8,719 codas recorded from approximately 60 sperm whales in the eastern Caribbean.

Rather than simply cataloguing individual calls, researchers examined how whales changed their sounds during interactions with one another.

What they found was remarkable.

The whales could alter the rhythm and tempo of their clicks while also adding subtle modifications to the sounds. Scientists called two of these features “rubato” and “ornamentation.”

These elements can be combined in different ways, creating a much larger repertoire of sounds than scientists had previously recognised. Researchers identified at least 143 frequently realised combinations in the dataset.

The whales appear to respond to one another

One of the most fascinating findings is that sperm whale communication does not appear to consist simply of animals making isolated noises.

Instead, the whales exchange codas in sequences that can resemble a conversation.

Some of the variations appear to depend on what another whale has just said, suggesting that the animals may modify their vocalisations according to the conversational context.

That is why scientists compare the system to aspects of human speech, text, Morse code and musical notation.

However, there is an important distinction: scientists have not yet translated the whales' sounds into human words.

They have identified the structure of the communication system, but the actual meanings of most of the sounds remain unknown.

Now scientists are finding ‘vowels’

The research has gone even further.

A 2026 study found that sperm whale codas can have acoustic characteristics that resemble human vowels. Researchers identified different coda qualities that show patterns comparable to features found in human phonetics and phonology.

The researchers say the similarities are striking enough that sperm whale vocalisations represent one of the closest parallels yet found between human phonology and an animal communication system.

This does not mean sperm whales speak English—or any human language.

Rather, it suggests that two very different species may have independently developed some similar principles for organising sounds into meaningful communication.

Artificial intelligence is helping crack the code

The enormous amount of whale vocal data would be extremely difficult for humans to analyse manually.

That is where artificial intelligence comes in.

Scientists involved in Project CETI are using machine-learning techniques to identify patterns in sperm whale vocalisations that might otherwise be almost impossible to detect.

AI can examine thousands of clicks and look for relationships between sounds, their order, timing and the behaviour of the whales producing them.

Researchers hope that continued analysis could eventually reveal what particular combinations mean.

The goal is not simply to create a “whale translator.” Scientists also want to understand how sperm whale societies function, how information is passed between generations and how different groups develop their own acoustic cultures.

Could whales have conversations?

The possibility is both exciting and humbling.

Sperm whales live in highly social groups and communicate underwater, sometimes across considerable distances. Their sophisticated clicking system may help them coordinate activities, maintain social relationships and share information.

But scientists remain cautious.

Finding structure in an animal's communication system does not automatically prove that the animals have language in the same sense humans do.

The crucial challenge is determining meaning.

Scientists need to establish what specific vocal patterns actually communicate and whether the whales consistently use them to convey particular information.

That work is still underway.

A glimpse into an underwater world

For centuries, humans have looked at whales as mysterious giants of the ocean.

Now technology is allowing scientists to listen to them in ways that were previously impossible.

The discovery of a complex phonetic system suggests that the underwater world may be filled with conversations humans have barely begun to understand.

And as artificial intelligence becomes better at recognising patterns in whale vocalisations, researchers may eventually be able to answer a question that has fascinated humanity for generations:

What are the whales saying to each other?

For now, scientists cannot give us the translation.

But they may have finally discovered the alphabet.