The Noises of nature

If you saw Bernie Krause, a sotto voce man with heavy, nearsighted eyes, seated amid the baffling array of high-tech sound-engineering gear in his Glen Ellen, Calif., studio, you might never guess that he was once flung down a Rwandan mountainside by a mountain gorilla. Or that he forced himself to sit coolly still in the stultifying blackness of an Amazon jungle night while a prowling jaguar mouthed a microphone he had set up only 30 feet down the trail.

As Krause tells these tales of peril, his voice resonates with a certain fearlessness developed during his worldwide, nearly 40-year quest to record the earth's rapidly disappearing "biophony" — a term he coined to describe that portion of the soundscape contributed by nonhuman creatures. Biophony, Krause has theorized, is unique to each place; nowhere in nature sounds exactly like anywhere else. This idea has led him toward a controversial way of thinking that would broaden the scope of today's evolutionary biology. Many animals, he argues, have evolved to squeeze their vocalizations into available niches of the soundscape in order to be heard by others of their kind. Evolution isn't just about the competition for space or food but also for bandwidth. If a species cannot find a sonic niche of its own, it will not survive.

Krause's "niche hypothesis" may seem more plausible after you've listened to his recordings of dense tropical jungles, polyphonous soundscapes packed with whistles and whinnies, whoops, hoots and howls, deep bass throbbings and shrieking buzzes. Krause employs supersensitive recording equipment and computer programs to create spectrograms of these group vocalizations, visual printouts indicating the stratified sounds according to time and frequency — not unlike a symphonic score. Using his trained eye, Krause is then able to locate the sonic signature of each animal. "What you're listening to is an animal orchestra, very finely tuned and constructed and conducted — there's no accident here," Krause says. "They all coalesce in a way that's not planned but cooperative or competitive, one creature in relation to another."

Western culture has long favored sight over hearing. But our distant ancestors, Krause claims, experienced the world through a more balanced use of their senses. He says he found evidence for this notion during a night hunt with the Jívaro tribesmen of the western Amazon Basin. While Krause struggled with the darkness, the Jívaro were able to note shrill warnings or sudden silences in the curtain of frog and insect sounds surrounding them and discern "which critter was 400 meters up the path, which way it was moving and whether it was worth hunting."

Today, however, we pay relatively little attention to what our ears pick up. Even our most pervasive form of mass aural communication, the television, is accompanied by visual images, and natural sound infrequently permeates our built environment. The literature on these transformations is meager. Krause found his early inspiration in the writing of the Canadian composer R. Murray Schafer, who coined the term "soundscape" in the 1960s and explored the impact of changes in the soundscape — like urbanization and industrialization — on our perception of our environment.

Krause turned his attention to Schafer and natural sound only after a long career in music, during which he became an early master of the Moog synthesizer and worked with the Doors, Van Morrison and Mick Jagger while contributing to hundreds of albums and film soundtracks. In 1968, he and his colleague Paul Beaver recorded "The Nonesuch Guide to Electronic Music." His focus on synthesized sound blurred during a casual conversation later that year. "Paul and I were having lunch with Randy Newman and Van Dyke Parks," he says. "One of them suggested, ‘Why don't you guys do something in ecology?' I had never heard that word before."

Intrigued, Krause went back to school, studying bioacoustics at Union Institute and University in Cincinnati in 1981. He began traveling to far corners of the world, taping animals from ants to elephants, tadpoles to killer whales. "Every organism has an acoustic signature," Krause says. One of his Aha! moments occurred in Venezuela, where Krause was recording warblers. "The birds would fly through grids of sounds until they found a place where their voices wouldn't be masked," he says. Krause noticed that birds who settled in compromised habitats — logged-over second-growth forests, for instance — encountered unexpected vocal competitors from other species and found their mating songs masked. Warblers that failed to find unoccupied bandwidth failed to breed, Krause observed, eventually convincing him of the validity of his niche hypothesis, the contention that animals evolve to fill vocal niches to best be heard by potential mates.

Some evolutionary biologists find troublesome ambiguities in Krause's hypothesis. Michael Greenfield, who specializes in animal communication and sensory evolution at the University of Kansas, says: "I don't know of any cases where you have a variety of species that basically have decided: ‘Let's all get along. You can have this bandwidth, and I'll have this, and that guy over there can have his piece.' There's little evidence that animals are solving this problem in a cooperative and amicable fashion."

Krause responds that Greenfield and others are too quick to dismiss the niche hypothesis. Competition, and not cooperation, is the driving mechanism by which he suggests that animals score complex and highly integrated soundscapes. Edward O. Wilson, the famed Harvard biologist, admits to an initial skepticism about Krause's work but says he ultimately finds legitimacy in it. "I assumed it was all a New Age thing, of little interest to scientists," Wilson wrote in a recent e-mail message. "I was wrong. ... His originality, research and above all basic knowledge of the sound environments in nature are impressive."

Unfortunately, just as Krause and his scientific progeny have begun investigating the possibility that an ecosystem's sounds are a key aspect of its health, they're witnessing those sounds' demise. In the decades Krause has been recording biophony — he has compiled a library of more than 3,500 hours of pristine natural sound, which he thinks is the world's largest private collection — nearly a third of the ecosystems he has captured have become aurally "extinct" because of habitat loss or the presence of noise-making machines. In this country, animals are continually forced to compete for bandwidth not only with one another but also with snowmobiles, off-road vehicles, Jet Skis and other loud motorized "toys."

Which is why, in addition to trying to find an archival home for his sound library — "so people can understand what we're losing" — Krause keeps trying to capture pure natural sound. Last spring he traveled to the Arctic National Wildlife Refuge to record the soundscape of springtime there. "If we don't take the opportunity to form a baseline understanding" of natural soundscapes, "we'll lose part of our own humanity," Krause says. "These sounds taught us to dance, and they're part of our language. I think we owe them something."