The Amazon rainforest at dawn

Gibbons in the Borneo rainforest

It is these sounds, the voices of our planet's creatures and environments, that world-renowned soundscape producer Bernie Krause has spent the last 30 years recording. Now based in Glen Ellen, California, Krause's work has taken him to the four corners of the globe; recording in the Amazon, Antarctica, Alaska, and at the research sites of Jane Goodall and Dian Fossey in Africa.  His library of natural sounds, the largest in the world, includes such unexpected vocalisations as the chirruping of microscopic underwater larvae and the amazingly noisy 'singing' of ants.

Bernie Krause in the field

It was Krause's notoriety in the music and film industry that brought him into contact with experimental artist Van Dyke Parks, at whose suggestion he was first to try recording natural environments. The album In a Wild Sanctuary was born, a synthesis of natural sound and music, and Krause began to dream of spending the rest of his life outdoors, recording.

By this time the egos and thanklessness of show business were wearing thin. "I didn't much like the smoke and collective angst that the music scene in the late 70s seemed to foster," says Krause. "The sounds of wild habitats became a much richer, more healing acoustic texture for me."

At the time, Bioacoustics was pretty much unheard of and Krause became one of only a handful on doctorates in the field. "My goal when I was beginning in the late 60s was to cast a wider net - one beyond the kind of the 19th Century idea of taking single species out of context to try to explain or understand aspects of the natural world," he says.

The idea of trying to capture the sounds of an integrated environment would become the cornerstone of Krause’s work. In his book Into A Wild Sanctuary he writes of an early morning when he was recording in Kenya and through the haze of his exhaustion began to hear insects and distant hyenas as though they were an animal symphony. Realising that perhaps this was not just a dream, he recorded the sounds to see if the effect would be the same when listened to later. It was. Analysing the material from Kenya, complex acoustic pattern appeared: different creatures were indeed vocalising in synch with one another.

After this experience, Krause began to spend more time recording the general ambient sounds of the places he found himself in. From this emerged what he calls his ‘niche hypothesis’, the idea that each creature vocalises in relation to all the natural sounds within an environment. An organism’s voice evolves to be complementary to other creatures in its habitat and occupying a distinct sonic zone is crucial to an animal’s survival. This differentiation and symbiosis of creature voices Krause calls a ‘biophony’.

Territory can be defined from an aural perspective, rather than charted on a traditional map, suggesting that it may not be possible for birds and mammals to simply move to a new area if their habitat is destroyed. Krause’s recordings of migrating eastern warblers, who learn to sing only one song in their lifetime, suggest that the birds may not be able to adjust when they when they return to find their South American nesting grounds destroyed. Although a new habitat may appear similar, territorial and gender-related communication is impaired.

It is also possible to date a location according to the number of vocal niches a creature occupies, indicating how long a particular voice has had to develop. In old ecosystems, like tropical rainforests, animal vocalisations may be specialised enough to occupy several niches. Listening, rather than looking, at an environment may be a more accurate way of measuring the damage done by humans.

Krause explains, “We're a visual culture. That's because the technology wasn't available until recently to capture sound with any quality. The problem is that the eye lies!  Take a forest where the logging industry has promoted selective logging. We are told that it has no effect on wildlife if done carefully. Sure enough: take a camera to a site that's been selectively logged, frame your shot and you'll get a beautiful photo. However, get a recorded example of that site before logging takes place and record the biophony. Then, record the site after the damage. You'll not only hear the difference immediately, but for years after."

I listen to two of Krause’s recordings which demonstrate this. Recorded before and after logging took place at Lincoln Meadow in the Sierras, the contrast is startling. In the first, a dawn chorus is an overwhelming cacophony of birds, vibrant with shrills, trills and warbles. The second is eerily quiet, there are only wind and stream sounds in the background and birdsong is subdued. Depressingly, in recordings from this site made 10 years after logging the biophony was still not recovering.

Lincoln Meadow at Yuba Pass, California, before logging

Lincoln Meadow at Yuba Pass, California, after logging 1 year later

While recording the chorus of spade foot toads around Mono Lake, near Yosemite National Park, Krause was able to witness the effects of human-made noise.  The way that frogs vocalise in unison masks the position of any individual voice, making it hard for predators to isolate a single creature. However, the disturbance to the biophony caused by a low-flying military jet took nearly an hour to mend during which time  two coyotes and a great horned owl opportunistically used the chance to feed.

In our noisy culture, we have come to accept a certain amount of assault on our ears: from cars, planes, loud machines.  Krause asks if perhaps we are making all this noise to replace what we lost when we silenced the natural world. Sadly, the sounds of the wild, in a state unpolluted by humans, is something that most people may never experience. Says Krause,  “I've become far more certain that our demise as a civilized species directly correlates with the loss of natural habitat and its attendant voice.”

Krause’s work has brought him into contact with people who are far more receptive to this audio information. In his book, he describes spending time with the Jivaro in the Amazon, who are able to distinguish between visually identical habitats simply by knowing how to listen. Even at night these people, using the biophony as an aural GPS, were able to locate themselves according to the differing sounds between areas as small as 20 square meters.

Krause’s library of recordings (over 3500 hours worth) is testament to the disappearance of soundscapes around the world. Returning to the same spots where once he could record an hours worth of useful material in 10 to 15 hours, he may now have to spend 2,000.  Krause estimates that 40% of the recordings he collected in North America are from habitats now extinct or so radically altered that the natural soundscapes can no longer be heard in any form.

However, Krause’s work is falling on receptive ears. His company, Wild Sanctuary shares his field-recordings through CDs and as part of large sound installations in public spaces such as museums, zoos and aquaria. Under Krause’s guidance, the National Park Service has recently mandated that natural soundscapes be protected in the same way as other precious natural resources.

Krause’s work reveals another layer of the natural world, one that is beautiful but  frail. When asked what hope he has left for our planets wild places, Krause replies, “It is only possible to halt the destructive process if we stop and listen and begin to re-learn that natural soundscapes are the sources of our language, our music, our spirituality and physical health. Once we get there, perhaps there's a faint glimmer of hope left for us.”