Listen to These Amazing Sounds of Lost Places and Animals Within Them

Prolific audio naturalist Martyn Stewart has released a free collection of his remarkable recordings before his passing

Panamanian Golden Frog
One of the species Stewart captured on audio is the Panamanian Golden Frog, a once-common species now rarely seen in the wild. Mark Newman via Getty Images

Martyn Stewart has always listened closely to the world around him. As a young boy, he explored the wild places near his childhood home in Birmingham, England, collecting insects, amphibians and other small animals in glass jars. Stewart recalls puncturing the jars’ tin lids, holding each up to his ear to hear the delicate sounds the creature made. Stewart soon borrowed a microphone from his teenage brother, an aspiring musician, and began documenting what he heard. “I used to go through my little world and record the sounds of nature,” says Stewart. “I believe the first bird that I recorded when I was 11 was the Eurasian blackbird.”

Now in his 60s, Stewart has amassed a collection of more than 30,000 hours of material, including birds, mammals, amphibians, reptiles, insects and entire soundscapes. The full-time audio naturalist started selling sounds from his personal collection after college, and his recordings have since been used in more than 150 films and numerous podcasts and nature documentaries. At least four of the species Stewart has recorded are now extinct in the wild, including the Panamanian golden frog and northern white rhinoceros. He estimates that two-thirds of his library captures soundscapes that have since been damaged or lost. The public can now access more than 200 of those sounds, a gift from Stewart meant to inspire conservation as he contemplates his passing.

Stewart, who was diagnosed with terminal bone cancer last year, recently released a free collection of albums in partnership with the Platoon Record label. The project, called Martyn Stewart's Listening Planet, is both a celebration Stewart’s contributions to the field of audio naturalism and his final effort to call attention to vulnerable places and animals. “There is going to be this huge audience listening to these gorgeous sounds, and it gives a voice for the animals,” says Stewart.

SmithsonianMag · Nature Sounds Recorded by Martyn Stewart

“We’re a visual culture and have, until very recently, studied the wild natural primarily through what we see,” says Bernie Krause, a soundscape ecologist and friend of Stewart’s, “but a much fuller understanding can be learned from what we hear.” Krause credits the rise in popularity of nature sounds, mediations and science recordings in part to the pioneering work of audio recordists like Stewart.

Nature sounds are now a multi-million dollar industry, with tens of millions of Americans using meditation apps to mentally transport to serene beaches or vibrant rainforests. “Martyn is one of the key handful of recordists who helped set the protocols and other standards that gave the work credibility and standing in the world of sound,” says Krause. “Few can match the quality of his life-long efforts.”

Martyn Stewart at Work
Stewart has made over 97,000 recordings throughout his life. Martyn Stewart

To build his library of sounds, Stewart has trekked to more than 40 countries, often lugging audio equipment through rugged landscapes to reach remote locations or animals. While recording, he sits quietly and listens through a headset, noting down different species and sounds he hears. Limiting his senses to a single input like sound reveals environments in new ways, says Stewart. One of his favorite places to record sounds is the Arctic National Wildlife Refuge, which can initially appear desolate. “It's not this white wasteland for 12 months,” he says. The frozen tundra is punctuated by the snorts of caribou and the fluted calls of migrating birds like red knots. “The soundscape shows how beautiful it actually is. It opens the door to another world that we hardly ever see.”

Since Stewart began documenting the natural world, the task has changed dramatically. To capture a few minutes of a frog’s chirp or a dolphin’s clicks can take hours of work because of nearly constant interruptions from noise pollution. “Twenty or twenty-five years ago, if I wanted to record one pristine hour of sound it would take about three or four hours to get that one hour. It was a brilliant world.” Today, Stewart notes that it would take around 2,000 hours to get a recording of similar quality. Sometimes, Stewart doesn’t realize his recordings are not up to par while he is in the field. The noise from cars, airplanes and other machinery is so subtle and ubiquitous that he often doesn’t discover interference that renders the files useless until he gets home.

Martyn Stewart Hiking With Equipment
Stewart, who was diagnosed with terminal bone cancer in December 2020, hopes his latest collection of recordings will spur species conservation. Martyn Stewart

Lang Elliot, a friend of Stewart’s and a fellow audio naturalist, remembers how noise pollution plagued a recent trip to Florida’s Everglades. Stewart and Elliot were elated when they captured a symphony of alligator bellows, but when they listened back to the audio at home, they heard machinery in the distance. “It was the most extraordinary recording either one of us had gotten, and here's this metallic spinning thing off in the distance making this horrible sound,” says Elliot. “We're just looking at each other listening to these recordings and, I wouldn't say on the verge of tears—in tears,” he says. Though they weren’t able to fix the recording, Elliot hopes he and Stewart will be able to make another attempt in the coming months.

Stewart estimates that the majority of the soundscapes he has documented in his career have now been touched by noise pollution. In some cases, a species he’s recorded in its natural environment can no longer be heard in that setting. One such species is the Hawaiian crow, an iridescent black corvid ​​that was once abundant throughout the islands but is now extinct in the wild.

From his first recording of a Eurasian blackbird as a boy, Stewart’s motivation has been singular: to use sound as a megaphone for vulnerable places and animals. By releasing a free collection of his most prized recordings to the public, he is optimistic those listening will feel closer to foreign species and environments, and feel motivated to act. “I hope they have the connection between sound and the animal emitting the sound,” says Stewart. “I think we have to become the voice of the voiceless. If we can get these beautiful sound recordings out and let people in the world listen to them, maybe we can start protecting what we've got left.”