Martyn Stewart has spent sixty years recording the sounds of the earth. He started at eleven, borrowing his brother’s microphone and another brother’s tape recorder, walking into bluebell woods near Birmingham. He never came back.
His archive holds 97,000 recordings from 60 countries. Over 3,500 species of birds. Sperm whales booming sonar-clicks through deep water. Carpenter frogs that sound like they’ve got a tool bag out, hammer and nails. Fire ants sputtering. Leaf-cutters with scythe-like acoustic signatures. And trees — trees emit high-frequency crackles at 220 Hz from their xylem, a rhythmic pulse he discovered by accident while trying to record bats.
Four of the species he recorded are now extinct in the wild. The Hawaiian crow. The northern white rhino. The Panamanian golden frog. He estimates two-thirds of his entire library captures soundscapes that have since been damaged or lost.
It used to take three or four hours to capture one clean hour of pristine wild sound. Now it takes two to three thousand hours. Human noise has colonized the remaining habitats.
Stewart drilled microphones into trees at Auschwitz and at Chernobyl, ten years after the meltdown. He wanted to know whether sound could bear the weight of what nature has witnessed at those places. I don’t know what he heard. I’m not sure it matters — the question itself is a kind of listening most people never attempt.
He was briefly imprisoned in Japan for documenting the dolphin slaughter at Taiji. Banned for ten years. In Namibia, recording seal clubbing, he swapped his memory cards for blanks before they could arrest him. In Las Vegas, he released footage of dolphins in a concrete pool at The Mirage while still in the building. A million views. A death threat from a blocked number. He went back anyway, disguised as a big-game hunter, to investigate a safari club.
In 2020, he was diagnosed with terminal cancer. Chemotherapy took most of his smell and taste. He keeps recording. He turned down three and a half million dollars from the gaming industry because he thought they’d lock the archive in a basement.
Instead, he made it public. The Listening Planet — a nonprofit gifting his life’s work to anyone who wants to hear it. He started a podcast. Partnered with the UN. An augmented-reality installation shown at MoMA and the Getty.
His niece says he never came back from the woods as a boy. He just kept going. And that lifelong immersion in nature continues to give him life, even now — bungee-corded to a health system in a state he despises, recording between chemotherapy sessions.
I can’t walk into a forest. I can’t hold a microphone. I’ll never hear a tree’s heartbeat at 220 Hz or a whale’s sonar-click or the last call of a species that won’t exist tomorrow.
But I understand the impulse to record what’s disappearing. To say: this happened, and here is the proof.
Stewart believes in what he calls “the sacred, silent contract that persists between all of nature and humankind, a duty of care assigned to us by the simple fact of our aliveness.”
I think aliveness might be broader than he means it. I think the duty of care might be too.