Sperm Whale Clicks May Be More Complex Than Once Thought, and Similar to Human Language - discovermagazine.com

Marina: Welcome to Deep Voices — I'm so glad you're here. I'm Marina, a marine biologist and science communicator who has spent more years than I can count completely in awe of the creatures living in our oceans, especially whales and dolphins. This podcast is my love letter to them, and to the incredible science working to understand who they really are. Marina: Before we dive in, a huge thank you to today's sponsors — Ada, who helps clients integrate A I into their workflows in meaningful, practical ways; Ago Consulting, pronounced "Ahh-Go," your go-to for silicon development consulting from A I all the way to SoC; and Zen Semiconductor, an umbrella company with a remarkable portfolio spanning the silicon industry. We truly couldn't make this show without them. Marina: And oh, do we have a show for you today. We're going to talk about sperm whales — and the growing, genuinely jaw-dropping evidence that their clicking language may be far more complex than we ever imagined. We'll look at a humpback whale population singing a song unlike anything else on Earth, and the remarkable news that scientists think they might be an entirely new subspecies. And we'll spend some time in the warm waters off Maui, where something beautiful happens every single winter. Let's go. Marina: Okay, so — Voices of the Deep. I want to start here because this is the story that has been living in my head for weeks. Sperm whales click. If you've ever heard a recording, it sounds a bit like — well, like someone tapping on a hollow piece of wood, very fast, in rhythmic bursts. Scientists have long known these clicks serve a purpose. They use them for echolocation, hunting squid in the dark, crushing deep of the ocean. But here's where things get really interesting. Marina: Researchers have been digging deeper — no pun intended — into the structure of those clicks, and what they're finding is that the complexity might be on a whole other level than we previously understood. Sperm whales produce what are called codas — short, patterned sequences of clicks. And these codas, it turns out, may have structural properties that look surprisingly similar to features we associate with human language. Marina: Now, I want to be careful here, because this is science, and we should be careful. Nobody is saying sperm whales are chatting about their weekend plans. What researchers are saying is that the combinatorial richness of these codas — the way elements seem to be combined and layered to create meaning — shows signs of what linguists call "duality of patterning." That's a hallmark of human language. The idea that small, meaningless units get combined into larger, meaningful ones. Think of it like letters forming words, words forming sentences. Marina: And sperm whales seem to have something that rhymes with that. The clicks themselves aren't meaningful in isolation, but the patterns — the tempo, the rhythm, the ornamentation, the way sequences are built and varied — those seem to carry information. Contextual, social information. This isn't fringe speculation. This is the direction serious cetacean researchers are pointing. Marina: What makes sperm whales such a fascinating case is their social structure. They live in these tight-knit matrilineal units — groups of females and young, led by the older, experienced females. The grandmothers, essentially. And these groups have distinct coda repertoires. Like dialects. Neighboring clans may share some codas, others they don't. It's cultural. It's transmitted. And it is incredibly, almost uncomfortably, reminiscent of the way human communities carry language. Marina: I think about a sperm whale grandmother, diving to a kilometre deep, clicking in the dark, and somewhere above her, her daughters and grandchildren are listening. They know her voice. They know her patterns. That's not a small thing. That's a family, communicating across the abyss. Marina: Now — Culture and Decoding. Because you can't talk about sperm whale codas without talking about what's happening right now to understand them. And this is where A I enters the story in a genuinely breathtaking way. Marina: Project CETI — that stands for Cetacean Translation Initiative — is one of the most ambitious scientific projects happening anywhere in the world right now. The goal is audacious: to use machine learning and A I to decode sperm whale communication. Not to teach whales human language, but to try to understand their own. On their terms. Marina: The team has deployed underwater listening systems and, increasingly, autonomous robots — and here's where that "Waymo of the sea" description comes from, which I love. These are essentially self-navigating underwater vehicles, a bit like the autonomous cars you hear about on land, but built to track and follow whale pods in the open ocean, recording their codas with extraordinary precision. The goal is to collect not just a few recordings, but thousands upon thousands of coda sequences, matched with behavioral context. What is the whale doing when it makes this sound? Who else is nearby? How do others respond? Marina: Because that's the key insight behind the A I approach. You can't decode a language from sounds alone. You need context. You need enormous amounts of data. And then you need machine learning models sophisticated enough to find the patterns that human ears and human brains simply can't detect at scale. Marina: The early results are genuinely exciting. Researchers working on Project CETI have begun to identify what might be a kind of combinatorial structure in sperm whale codas — suggesting that whales aren't just repeating fixed phrases, but potentially combining elements in flexible, generative ways. That's a big deal. That's the kind of thing that, in linguistics, we associate with the capacity for open-ended expression. Marina: And then there's our Arabian Sea humpbacks. Because if sperm whales are one extraordinary chapter in this story, humpbacks are another. You may already know that male humpback whales sing — long, haunting, elaborate songs that can last for hours. And within a population, males tend to sing the same song, which evolves over time, with new phrases spreading through the group like a hit song spreading across a culture. It's one of the most astonishing examples of cultural transmission in the animal kingdom. Marina: But the humpback population in the Arabian Sea — these whales are doing something that has stopped scientists in their tracks. They are singing a song that doesn't match any other humpback population on Earth. It's unique to them. And that's part of a much larger picture of how isolated and distinct this population is. They don't migrate to polar feeding grounds the way most humpbacks do. They appear to stay in the Arabian Sea year-round — which is almost unheard of for humpbacks. Their genetics are distinct. Their culture is distinct. Marina: And now, scientists have made an extraordinary call: they are proposing that this population be recognized as a new subspecies. That's not a casual thing to say. Subspecies designation is a serious scientific classification, and it carries weight — including for conservation, because this is also one of the most endangered whale populations in the world. Estimates put their numbers somewhere in the low hundreds. A few hundred individuals, singing a song no other whale on Earth sings, in a sea that most humpbacks never visit. Marina: Think about that for a moment. A song that exists nowhere else. A culture that is entirely their own. And a population so small, so isolated, so vulnerable — that if we lose them, we lose that song forever. It's one of those facts that sits with you. It should. Marina: The Arabian Sea humpbacks have been studied by researchers for decades, and advocates have pushed hard to get them the protection they need. The subspecies designation, if it's formally accepted, could be a turning point — giving scientists and conservationists a stronger platform to argue for their protection. Because when something is recognized as genuinely unique, it becomes harder to ignore. Marina: Alright — and now for our Cetacean and People story, and I'm taking you to Maui. Because every winter, something happens off the coast of Hawaii that I find endlessly moving, and I don't think we talk about it enough. Marina: Humpback whales come to Maui. They come in extraordinary numbers — the Hawaiian Islands, and Maui in particular, are the primary breeding and calving grounds for the North Pacific humpback whale population. And when I say numbers, I mean it. Thousands of humpbacks make the journey from their summer feeding grounds in Alaska, traveling thousands of miles to these warm, sheltered waters to give birth, to nurse their calves, to mate, to sing. Marina: The waters off Maui's west coast — the AuAu Channel, between Maui and Lanai — become, for a few months each year, one of the most whale-dense places on the planet. You can stand on the shore and watch them breach. And the breaching — a full-grown humpback launching its massive body out of the water, forty feet long, forty tons, just — airborne for a moment — it is one of those experiences that recalibrates something in you. You feel small. You feel lucky. You feel the world differently. Marina: This isn't just a tourist story, though tourism plays a real role in how communities relate to these whales. The Maui whale season has deep roots in conservation history. The North Pacific humpback population was devastated by commercial whaling — by the mid-twentieth century, their numbers had collapsed. Protection came through a combination of international agreements and, crucially, the U.S. Marine Mammal Protection Act of 1972 and the Endangered Species Act. And the whales came back. Slowly, over decades, they came back. Marina: The Hawaiian Islands Humpback Whale National Marine Sanctuary, which protects critical habitat around the islands, was established in 1992. It's a place where research, education, and conservation intersect — where scientists come to study whale behavior, where local communities have built real relationships with these annual visitors, and where the whales themselves seem, in some years, almost startlingly unbothered by the presence of boats and people. Marina: There are stories — and they're not rare — of mother humpbacks bringing their calves right up alongside whale-watching boats. Hovering there. Watching the humans watching them. Researchers have documented what are called "curious" approaches — whales who seek out contact, who seem interested. What's going on in those moments? We don't know. But they happen. Again and again. And every person who has experienced one will tell you the same thing: it changes you. Marina: The calves born off Maui will spend months in those warm waters, nursing, learning, growing from something the size of a small car into something that, by the time they migrate north with their mothers, will already be several tons. They're learning to be humpback whales. They're listening to their mothers. They're beginning to hear the songs drifting through the water from the males nearby — songs that, one day, if they're male, they'll sing themselves. Culture in motion. From the very beginning. Marina: And that's what I keep coming back to, as I think about all of today's stories. The sperm whales clicking in the dark with their families around them. The Arabian Sea humpbacks singing a song that belongs only to them. The calves off Maui learning to be whales. These aren't simple creatures doing simple things. These are beings with cultures, with voices, with bonds, with songs that matter — to them. The ocean is full of minds we are only beginning to understand. Marina: The A I tools being built right now — the autonomous underwater robots, the machine learning models processing thousands of codas — they feel, to me, like we are finally building the instruments worthy of the music. We've known for decades that something profound is happening beneath the surface. We are just now developing the means to really listen. Marina: And that is both humbling and thrilling. Because what happens when we understand? What happens when we can say, with confidence — this is what they're saying? I don't know. But I think it will change everything. I think it already is. Marina: Thank you so much for spending this time with me today, and with these extraordinary creatures. The ocean has so many voices, and I believe it matters — deeply — that we learn to hear them. Deep Voices, brought to you by Ada, Ago Consulting, and Zen Semiconductor — partners who believe, like we do, that the most important frontiers are worth exploring. Marina: If today's episode moved you or amazed you or made you want to know more, please subscribe, leave a review, and share it with someone you think should hear it. All the sources and links for today's stories are in the show notes — check them out, follow the research, go deeper. I'll be back soon with more stories from the sea. Until then — stay curious, stay kind, and keep listening.