In 2015, whale researcher Valeria Vergara pitched a tent on Somerset Island in the Canadian high Arctic, surrounded by fog so thick she couldn't see her hands. She dropped a hydrophone into the water and was instantly immersed in the chattering of beluga whales - a cacophony of clicks, squeals, and whistles. She realized, in a moment of empathy, that the whales live in a similar fog but stay deeply connected through sound. "Oh my God, this is really what it means to live in a world of sound," she thought.
Since the first recording of whale song in 1949, researchers have been captivated by whales' wails, rumbles, and grunts. Sound is the fabric of their sociable lives: they sing in breeding grounds, chatter during birth, and echo-locate to find food. Different species have dozens of dialects, and their communication shows parallels with human speech. Whales also produce the loudest sounds of any animal - the same sounds that once rattled the wooden hulls of whaling ships.
Now, with new analytical technologies, insights are piling up. In an era when most whales are protected from hunting but face other threats, researchers ask: what clues do their sounds hold to protect them from a noisier, warmer, more unpredictable ocean?
Acoustic data is a relatively easy way to gather information: a single hydrophone can record years of sound. This eavesdropping has yielded discoveries both delightful and profound. Vergara, now director of the cetacean research programme at Raincoast Conservation Foundation, found that baby belugas learn to communicate from adults, and they babble like human toddlers. "It will take them a good two, three years to become proficient," she says. They perfect an "acoustic name tag" to identify themselves, but her recent work shows that baby belugas' calls have an underwater range 18 times smaller than an adult's, making them easily masked by boat noise. This could mean separated calves get permanently lost.
Thanks to research by Vergara and others, in 2018, Canadian authorities closed key beluga meeting grounds to boats, letting the "faint, tentative, underdeveloped calls of little calves" be heard. Vergara sees this as proof that acoustic monitoring matters: "There are so many things that humans can do."
Belugas are chatty, but all cetaceans have diverse vocal repertoires. Some share distinctive sounds within their populations, teaching and learning from each other, driving hundreds of unique dialects. These dialects often correlate with unique behaviours like foraging and migration. For example, a distinct group of 74 endangered orcas in the Salish Sea has keening whistles and squawks. Raincoast scientists are linking calls to habits using drone footage, aiming for targeted conservation measures that go beyond "a blanket statement that [shipping] noise is bad."
It was once controversial to suggest whales have culture - socially shared behaviours like dialects. Now it's accepted that many species have cultural traditions. Take humpback songs: only males sing, composing units into "phrases," repeated into "themes," arranged into unique songs. Dr Ellen Garland of St Andrews University studies South Pacific humpbacks. "I like to think of this as movements in a symphony," she says. Males sing for reasons not fully understood, but each group has a unique, constantly evolving song that all males learn together. Garland discovered that songs spread in an unstoppable wave across the South Pacific, from west to east. "Within a season, [a population will] literally throw what they have out the window and rapidly learn this completely new song from their neighbours," she says. "No other animal does these rapid and complete population-wide changes, except for humans."
These "cultural waves" are important for conservation. Taylor Hersh of Bristol University studies sperm whales, which produce complex clicking sounds called "codas." Pacific clans have a preferred coda that acts as an "identity coda," distinguishing populations. Why? "Our best guess is that it reinforces their bond," she says, jokingly comparing it to saying "American!" and getting "American! American!" in response. These codas can function like geotags, helping researchers match whale behaviours to ocean conditions. "In most parts of the world, things are getting worse for animals," Hersh says, so cultural insights are crucial.
Beyond conservation, Hersh enjoys the whales' auditory landscape. Sperm whales have "really beautiful societies" structured around female relationships and are peaceful. "Anything that knocks human exceptionalism down the peg is good in my book!" she says.
Project Ceti, a US nonprofit, is training machine-learning AI on sperm whale communication off the Dominican coast, aiming for translation. They found that sperm whales use different codas in different contexts, and with gaps removed, some codas sound like "vowels." They also change codas in the presence of shipping noise, suggesting controlled meanings. Gašper Beguš, linguist lead, believes this "is reframing how we think of language." This is controversial among cetacean researchers, but there's broad agreement that understanding whale communication helps improve their protection. Beguš notes that language has long been a legal barrier to rights, and showing a blurry line means we should push for expanding rights to whales. Indigenous Polynesian peoples already recognize whales' legal personhood.
Will we ever speak to whales? Some have tried playback experiments, but these can confuse cultural exchanges and cause distress, so they're now ethically fraught. Vergara says the question misses the point: "This idea that we are going to talk to whales puts us suddenly at the centre of things. Why do we need to go there for something to be fundamentally important?" Instead, understanding how whales communicate can reveal how to protect them. Recalling the beluga cacophony, her question was not what they'd say to us, but how their trills and squeals help them survive - and what that can teach us about helping them. "It was such a moment of clarity," she says.