There are lots of ways to monitor natural environments. You can count animals, track temperature, measure ice thickness, use time-lapse photography. A surprisingly powerful and direct method is to listen — to record the sounds of a habitat and observe how they change over time.
The work of taking and analyzing these recordings occurs in an area of study known as ecoacoustics. It’s a unique kind of discipline, with elements of both art and science, and it’s this combination that drew Bernie Krause to the work nearly 50 years ago. In the late 1960s, he was a professional musician working on an album called “In a Wild Sanctuary” that combined natural soundscapes with instrumentation. In the process of recording those soundscapes, Krause realized he was in the wrong line of work.
“They were the most beautiful sounds I’d ever heard,” Krause says. “No music could compare, and I decided right then and there that [recording soundscapes] was what I wanted to do with the rest of my life.”
Soundscapes are the acoustic equivalent of a landscape image, explains Gianni Pavan, who studies bioacoustics at the University of Pavia in Italy, in an e-mail. They can include biological sounds (everything from birds chirping to carpenter ants rubbing their legs on their abdomens) non-biological natural sounds (distant thunder, trickling streams), and manmade sounds, like snowmobiles whipping through Yellowstone.
Over the years Krause has recorded more than 5,000 hours of audio, which is collected, in a sense, in a new book, “Voices of the Wild,” that can be read in coordination with a website where the audio clips are stored. The book features recordings from all over the world, from coral reefs off Fiji to the desert in New Mexico. Krause explains he finds soundscapes from Alaska to be particularly magical “because they’re so fragile and because they’re so expressive and wonderful at their peak.” He doesn’t have any from New England, however, because he says in such a densely populated area it’s hard to find places where natural sounds aren’t unduly affected by human activity, like planes flying overheard or lobster boats idling offshore.
Krause’s soundscapes are interesting and often beautiful. They also come with a political message. He estimates that nearly half of the habitats he’s recorded have either “gone silent” over the last 35 years or been radically altered by human activity.
To make this point, he sent me an audio clip that compares recordings taken at Sugarloaf State Park in California in 2004, 2009, 2014, and 2015. There’s an unnerving finality to the way the sounds peter out as time goes on, an effect Krause attributes to the region’s prolonged drought.
Despite this gloomy trend, Krause remains celebratory in the way he approaches his work. Last year he debuted a symphony based on natural soundscapes and this past June a ballet for which he wrote the score premiered at the Jacob’s Pillow Dance Festival in Becket, Mass. With these projects and his book, he hopes to bring home just what we stand to lose as the environment around us recedes and changes.
“While I’m not terribly optimistic,” he says, “I am hopeful that we’ll begin to hear the message these critters are putting out in time to do something about saving them.”
Kevin Hartnett is a writer in South Carolina. He can be reached at email@example.com.