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Are you speaking my language?
We know that whales are mammals, just like us. They breathe air, are warm-blooded and give birth to live young. Some whales, like the humpback whale, have an artistic flare and can sing songs! But what we also share with these gentle ocean creatures is their communication; they speak a secret language that we have been trying to decode for years.
Sperm whales (Physeter macrocephalus), the largest toothed predator on Earth, live in close family groups called clans that are centred around social bonding1. They communicate using a short pattern of clicks known as “codas”. These codas are important for coordination between different members of the group – such as between mother and calf, or older females who often babysit calves around the time of their birth (adorable, I know!). In some ways, their societies don’t seem so different from our own.
But just how similar is sperm whale language to ours? Emerging research led by Gašper Beguš and a team of specialised linguists and marine biologists at Project CETI suggests sperm whales might not just be using different click patterns to alter meaning, but that they also use different vowel-like sounds similar to human speech.
This discovery isn’t just another cool fact to add to the encyclopaedia. Understanding their language means we can work towards protecting them. Threatened by ship strikes, noise pollution and entanglement with fishing gear, sperm whales are currently listed as vulnerable, with an estimated 300,000-450,000 left in the wild2. If scientists can understand how sperm whales communicate, socialise and navigate the ocean, then then it may reveal important information to help us safeguard their populations in the future.
For this reason, Beguš et al. set out to further investigate different dimensions of sperm whale vocalisations…
Cracking the Codas
So how exactly were the scientists eavesdropping on sperm whale conversations?
Researchers used four years of recordings of nearly 4,000 codas from 15 sperm whales off the coast of Dominica in the eastern Caribbean. They measured these vocalisations using underwater microphones (hydrophones) and digital acoustic tags (Dtags) which are attached to the skin of the whale through a suction cup and are designed to be minimally invasive. Connecting tag with whale is a difficult procedure to carry out from the side of a boat, as you can imagine – relying not only on skill, but also on a fair bit of good luck! Everything must come together at the last second to successfully attach the tag – the angle of the boat, the drone, and of course the cooperation of the whale to breach the surface at just the right moment. These fantastic devices can also capture additional information such as water temperature and depths reached by the animal3.
Then came the difficult part: figuring out the aspects of all those clicks.
For years, scientists have studied codas mainly through rhythm (timing between clicks), tempo (click duration), ornamentation (presence of extra clicks) and rubato (how the duration of clicks is maintained) – almost like analysing beats in music. But Beguš et al. (2026) uncovered something far more surprising. The clicks seemed to fall into two distinct sound categories: some had one main sound peak, while others had two.
Using computer algorithms to analyse each click, the team labelled these sounds “a-codas” and “i-codas” because they loosely resembled human vowel sounds like “ah” and “ee”.
And the whales weren’t using them randomly. Some codas consistently favoured one sound type over another, suggesting sperm whales may actively choose different sound patterns, similar to how humans choose different vowels and words while speaking.
The similarities didn’t stop there. The researchers found that a-codas tended to last longer, while i-codas were shorter, just like how “ah” naturally takes longer to say than “ee”. Some whales also consistently produced faster or slower codas than others, hinting at individual speaking styles. The differences between individual whales can be seen in the graph below, with each whale using the two types of coda at slightly different frequencies.
Then came one of the most human-like discoveries of all. Sometimes the first click in a coda changed depending on the coda that came before it. Linguists call this coarticulation, the tiny way sounds influence one another during speech. You do it constantly without noticing. Try saying “bad” and “bag”. The “a” sounds almost identical, but your tongue subtly changes position depending on the next letter.
Human speech is fluid, connected and constantly shifting. These findings suggest that Sperm whale communication may be just as similar and complex than we ever imagined.
What’s all the commotion in the ocean?
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If sperm whales really do have an incredible complex communication system, then threats like ocean noise pollution may not just be interrupting sounds, but also conversations.
We all know how frustrating it can be trying to talk when the phone starts cutting out, there’s a really loud group on the next table or someone’s just blasted their music on the speaker. For sperm whales, this is happening too. Human-made noise from ships, military sonar and industrial activity can drown out the clicks they rely on to navigate and hunt, and potentially also the important messages they send to one another with their codas. Research has suggested that sonar produced by naval technology can lead to changes in behaviour such as reducing their feeding effort, altering their diving behaviour or even drive them away from habitats4, reshaping their entire world.
These behaviours could be identified by changing vocalisations, so learning the language of sperm whales could be the key to protecting them and tracking their location. The SAvE Whales project carried out by OceanCare is doing a lot of brilliant research around using high-tech hydrophones to measure and locate sperm whale sounds in real time, which is useful for mitigating problems such as ship strikes5. Knowing how these animals behave around ships can pave the way to implementing better measures such as modifying shipping routes or creating speed reduction zones where whales are most active.
How to find Another Way
Protecting sperm whales doesn’t always mean having to do something huge. It can start with helping to look after sperm whales’ home by choosing sustainable fish, and paying attention to the oceans beyond documentaries and headlines: supporting organisations researching marine conservation, or even following projects like Project CETI and OceanCare, which are working to better understand and protect whale populations.
Maybe conservation doesn’t begin when we finally learn to speak to whales, maybe it begins when we learn to listen.
Written by Charlene Desouza.
Want to know more?
If you want to simply learn a little more about sperm whales, ORCA has an incredible fact file page with a pretty cool photo gallery of sperm whale sightings.
Project CETI– A groundbreaking research project using AI and underwater recording technologies to try and decode sperm whale communication. They have a very cool website and fantastic social media pages that explain all the whale science!
OceanCare- A marine conservation organisation committed to creating healthy and resilient oceans, including their three-year pilot project, SAvE Whales, which uses underwater microphones to reduce ship strikes and protect whale populations from ocean noise pollution.
After the Breach Podcast– A channel for any whale enthusiast exploring topics from endangered Southern Resident orcas to special whale encounters in the Salish sea.
NOAA Ocean Noise– Explore a range of resources with the NOAA, including their ocean Acoustics Program, Ocean Noise Strategy and other research programmes taking place all over the globe.
References
Primary source:
Gašper Beguš, Maksymilian Dąbkowski, Ronald L. Sprouse, David F. Gruber, Shane Gero (2026) ‘The phonology of sperm whale coda vowels’ Proc Biol Sci 293 (2069): 20252994. https://doi.org/10.1098/rspb.2025.2994
Other sources:
1Francois Sarano, Justine Girardet, Véronique Sarano, Hugues Vitry, Axel Preud’homme, René Heuzey, Ana M. Garcia-Cegarra, Bénédicte Madon, Fabienne Delfour, Hervé Glotin, Olivier Adam, Jean-Luc Jung (2021) ‘Kin relationships in cultural species of the marine realm: case study of a matrilineal social group of sperm whales off Mauritius island, Indian Ocean’. R Soc Open Sci 8 (2): 201794. https://doi.org/10.1098/rsos.201794
2North Atlantic Marine Mammal Commission (2025) ‘Sperm Whale’. Available at: https://nammco.no/sperm-whale/
3Gubnitsky, G., Mevorach, Y., Gero, S., Gruber, D.F. and Diamant, R. (2025) ‘Automatic detection and annotation of eastern Caribbean sperm whale codas’ Scientific Reports 15, 12790. Doi: https://doi.org/10.1038/s41598-025-97009-z
4 Isojunno S, Wensveen PJ, Lam FA, Kvadsheim PH, von Benda-Beckmann AM, Martín López LM, Kleivane L, Siegal EM, Miller PJO (2020) ‘When the noise goes on: received sound energy predicts sperm whale responses to both intermittent and continuous navy sonar.’ J Exp Biol. 223 (Pt 7): jeb219741. Doi: 10.1242/jeb.219741.
5 Skarsoulis EK, Piperakis GS, Orfanakis E, Papadakis P, Pavlidi D, Kalogerakis MA, Alexiadou P and Frantzis A (2022) ‘A Real-Time Acoustic Observatory for Sperm-Whale Localization in the Eastern Mediterranean Sea’ Front. Mar. Sci. 9:873888. Doi: 10.3389/fmars.2022.873888
