Sound track from nature

For 40 years, American bioacoustician and author Dr Bernie Krause recorded natural sounds from habitats around the world. Today 50 per cent of his sound library, the world's largest, comes from now extinct areas.

Flapping wings, hoots, growls and animal movements. Or pitched wind, lashing rain and ocean waves. Or chainsaws, aircraft, vehicles and machinery.

Define noise.

To most, these are pervasive sounds, mere frequencies that are superficially relevant. But to a bioacoustician who records natural sound, each chirrup, buzz, gurgle, stridulation and rustle is context to understand the ecosystem and measure our cultural success.

Since 1968, American bioacoustician and author Dr Bernie Krause has recorded natural soundscapes or acoustics from an environment that reach the human ear. These provide data for research related to habitat degradation.

Bernie has visited environs from the tropical to the Arctic, from the desert to the marine, and found himself flung down a Rwandan mountainside by a gorilla; forced to sit still in an Amazon jungle while a jaguar tried to eat up a microphone set up nine metres away; and lured a stray humpback whale from the Sacramento River Delta back to the Pacific Ocean.
His library, the world's largest private collection, has more than 3,500 hours of soundscapes from Brazil, Peru, Zimbabwe, Tanzania, Rwanda, Indonesia, Antarctica, Alaska, New Zealand, Australia, Fiji, Hawaii and the Caribbean and North and Central America.

Almost 50 per cent are from now extinct areas, admits Bernie ruefully. "In extinct locations, the soundscape is so radically altered or non-existent that it can no longer be heard."

Bernie loves the task of recording. He works in the boondocks, suffering extreme weather conditions, often alone. He doesn't fear the natural world, but the most difficult part he says "is to find a natural place where wildlife expresses itself acoustically".

When he started out, he would record for 10-15 hours to capture an hour of useable material. "Now it takes nearly 2,000 [hours] to get the same result," he says. He laments that unaltered surroundings are rare and portends there may be none left within this century. "The culprit is primarily human activity, whether proactive resource extraction or noise," he says.

Bernie's soundscape albums, through his company Wild Sanctuary, are used in museums, zoos, aquaria, retail and other public spaces in the US. His commissions are at several institutions, notably the Smithsonian Institution in Washington DC, South Carolina Aquarium and American Museum of Natural History in New York. His latest book is Wild Soundscapes: Discovering the Voice of Natural World.

He has collaborated with Google Earth to develop soundscape zooms to give a new layer of acoustic meaning to the visual Google Maps. He says, "Each location has a unique voice, like a fingerprint. For several years, Google Earth never thought to add an audio component."

Nature's rhythm

The first time Bernie recorded an animal – mammal, amphibian, reptile, insect and bird – orchestration in Kenya in 1983, he realised that each note was akin to an instrument in an orchestra. (Prior to this, he recorded isolated creature voices within an environment.)

He printed a spectrogram – a visual representation of sound. "It resembled a contemporary music score, a glorious symphony," he says, adding that he discovered all vocal creatures are heard in harmony to one another and each creature has a separate bandwidth.

He speaks of the loss of aural acuity that used to be central and our proclivity to rely greatly on sight and image. He recounts his adventure with the indigenous Jivaro tribe in the Amazon Basin where he accompanied the men on a night hunt. The hunters found their way through dense foliage without torches, guided primarily by subtle changes in forest sounds. They accurately described unseen animals far down the path by listening to the slightest variation in insect and frog articulations.

He explains how ancient tribes used to hunt by listening to game and other creatures hundreds of metres away. "The Ba'Aka in Central African Republic and Kaluli in Papua New Guinea still depend on their ability to hear and understand audio and visual information. They can also recognise subtle differences in sound between mini-habitats as small as 20 square metres even when the biological and geological components seem identical."

His work in the wilderness has taught him to observe time differently. "Humans have divided the day into 24 hours, each hour into 60 minutes of 60 seconds. For the natural world, the day begins at dawn, not at 0000 hours; time is expressed though natural rhythms, which is relaxing."

His experience has also prepared him to work "within the limits of uncertainties in the wild". Bernie is more terrified to walk alone on the streets of New York, Paris, London or Johannesburg than "in forests with reptiles and pouncing cats".

Human-induced noise

Bioacoustics helped Bernie understand habitat loss and "the effect of human-induced noise to convey aspects of damage".

He says, "Wild soundscapes serve as an analgesic. Noise affects the behaviour of wild creatures and impacts human health." There is a correlation between human-induced disturbances in natural and urbanised settings. Some of the factors imputed are human mechanical noise, unmitigated resource extraction and lack of knowledge.

"We pay little attention to what our ears pick up," he says, stating minimal value is ascribed to auditory stimuli. In urban cities, "noise, which is emblematic of power, generally causes stress. The sounds from iPods, video games and other digital technologies mask those of industrial and natural sources."

The only way to ameliorate the problem is to integrate with nature. And though this suggestion isn't always practical, Bernie says, "It is the only way to recalibrate our sensitivity to sound – re-learn the art of listening in the ways our ancestors used to at virtually no cost."

Bioacoustics – its applications

Bioacoustics is a branch of acoustics that explores the relationship between living beings and their environment. The field emerged from R. Murray Schafer's work in the late '70s at Simon Fraser University in Canada.

A world-renowned composer, he introduced the concept of soundscape in his book Tuning of the World, which Bernie expanded with biophony, geophony and anthrophony.
"I introduced biophony [biological sounds] in my '98 autobiography Into a Wild Sanctuary.

Then in 2002, geophony and anthrophony were invented to describe natural non-biological and human-induced sounds by my co-author Stuart Gage of the Michigan State University's Envirosonics Laboratory and myself. At the time, we were commissioned to complete a US National Park Service soundscape resource programme," he says.
Bioacoustics also contributes to biology, anthropology, medicine, philosophy, human music, literature, physics (acoustics) and mathematics.

Fieldwork

When Bernie first started out, he used to carry about 80 kg of recording equipment – audiotapes, batteries, microphones and cables – on a monthly field trip. Today he carries less than six.

"Digital equipment has made this possible," he says. Bernie doesn't carry a laptop on field trips; he works on analyses at his laboratory in California. Nowadays, he spends extended periods of time to get 15 minutes of useable material. "The long wait is primarily due to human-induced mechanical noise from chainsaws, aircraft, motorcycles, vehicular traffic or motorised riverboats more than 30 km away." Until recently, Bernie spent an average of seven months in a year
in the field.

"I am getting older and the endeavour is harder. After all these years of eating insects and grubs, it is nice to eat my
wife's cooking! But I'm happy my work is being accepted for the valuable resource I've always thought it to be."

For more information, email chirp@wildsanctuary.com