Scientists Decode Sperm Whale Communication

Scientists using artificial intelligence have identified structured communication patterns in sperm whales, including 156 distinct codas and repeated click sequences that function as a phonetic-like system. The research has been linked to Project CETI, a non-profit international initiative founded in 2020 with a base in Dominica.

Sperm Whale Communication

Sperm whales are toothed whales in the family Physeteridae and are known for producing codas, which are short sequences of clicks used in social communication. Researchers have recorded vocalisations from about 400 sperm whales in the Eastern Caribbean between 2005 and 2018, including data from at least 60 individual whales.

Project CETI and AI Analysis

Project CETI stands for Cetacean Translation Initiative and brings together marine biologists, AI researchers, roboticists, theoretical computer scientists, and linguists. On 7 May 2024, research published in Nature Communications and co-led by MIT’s Computer Science and Artificial Intelligence Laboratory proposed a “sperm whale phonetic alphabet” based on contextual and combinatorial structure in codas. Researchers identified two notable features in the vocal patterns. The first is “rubato”, which refers to changes in tempo and rhythm. The second is “ornamentation”, which refers to the addition of an extra click to a coda.

Regional Dialects and Recording Tools

A study dated 9 July 2026 found that sperm whales in the eastern Mediterranean Sea use a distinct regional dialect from western populations. In December 2025, Harvard engineers working with Project CETI developed an open-source bio-logger that attaches to sperm whales and records high-fidelity multi-channel audio, behavioural data, and environmental data for machine learning analysis. On 1 May 2026, Project CETI researchers also developed an autonomous underwater glider for real-time tracking and recording of sperm whale vocalisations. The glider uses buoyancy for quiet movement and onboard software to steer towards whales.

Important Facts for Exams

• Sperm whales belong to the order Cetacea and are the largest toothed whales on Earth.
• Codas are sequences of clicks and are a key feature of sperm whale social communication.
• Nature Communications is a peer-reviewed scientific journal that publishes research in the natural sciences.
• Dominica is an island country in the Caribbean and serves as the base of Project CETI.

AI, Linguistics and Marine Biology

The Open Mind study published on 12 November 2025 used AI and linguistic analysis to suggest that sperm whales may use “clacks” instead of clicks in some contexts. Marine biologists have also raised concerns that some of these signals may be recording artefacts.