Advanced Search

Please click here to take a brief survey

Acoustic Ecology and the Extinction of Silence
Sarah Rich, 21 Jan 07
Article Photo

For several years, I lived in an apartment in San Francisco where my bedroom window faced directly onto Haight Street. The quietest time of day fell somewhere between the bar-hoppers and homeless retiring to their respective sleeping quarters, and the early cooing of pigeons and idling of delivery trucks. But that's not to say it was ever truly quiet. Like most city-dwellers, the sounds of the street became more peaceful than silence, in a way, and I didn't really mind the near-continuous melodies of horns, sirens and voices. Sound, like smell, is something we adapt to much more quickly than physical changes in our surroundings. But the behavioral changes we make according to our soundscape can in fact be a powerful indicator of environmental and cultural trends in our region.

Even more powerful are the adaptations we can observe in wildlife as their habitat changes due to the presence of human activity. This is the primary focus of the Acoustic Ecology Institute, a New Mexico-based non-profit working to "increase personal and social awareness of our sound environment, through education programs in schools, regional events, and our internationally recognized website," and to build "a comprehensive [online] clearinghouse for information on sound-related environmental issues and scientific research."

Perhaps the best way to understand their work is to hear about a few examples offered up in their recent news posts:

Study Confirms Birds' Changing Songs in Cities - Field studies in ten European cities, including London, Paris, and Prague, have confirmed that great tits adapt their songs to be better heard above a variety of noise conditions. The city-dwelling birds, a species that has adapted well to urban settings, were compared to forest-dwelling birds nearby. In songs important for mate attractions and territory defense, the urban songs were shorter and sung faster than the forest songs. The urban songs also showed an upshift in frequency that is consistent with the need to compete with low-frequency environmental noise, such as traffic noise. The capacity of great tits to sing within a relatively wide frequency range, and the ability to adjust songs by leaving out lower frequencies, seems critical to the bird's ability to thrive despite urban noise. Species without these capacities may have no other choice than to escape city life. An earlier study by the same researchers had identified frequency differences in great tit songs in one urban area, reflecting the amoung of low-frequency noise they had to be heard above; this study expands the findings to include many populations of tits, and compares urban to rural populations.

Another story that struck me for its artistic quality is the installation of "One Square Inch of Silence" in Olympic National Park by natural sound recordist and master listener, Gordon Hempton. His project stood as a call to the National Park system to establish sonic refuges within park boundaries, where increased visitor traffic has tainted the purity of the soundscape and generally raised the volume throughout the otherwise protected acreage. "Quiet is going extinct," he says. His installation can be found by following directions on his website. Visitors are invited to scrawl their impressions quietly on a piece of paper and leave them in a jar at the site.

It's not just about nature and wildlife, though. The AEI tracks advances in science and medicine through sound, such as a study published by the Optical Society of America illuminating the possibility of early detection of metastasizing melanoma by listening to sounds emitted by cancer cells:

The unprecedented, minimally invasive technique causes melanoma cells to emit noise, and could let oncologists spot early signs of metastases -- as few as 10 cancer cells in a blood sample -- before they even settle in other organs...The team's method, called photoacoustic detection, combines laser techniques from optics and ultrasound techniques from acoustics, using a laser to make cells vibrate and then picking up the characteristic sound of melanoma cells. The microscopic granules of melanin contained in the cancer cells absorb the energy bursts from the blue-laser light, going through rapid cycles of expanding as they heat up and shrinking as they cool down. These sudden changes generate ultrasonic sounds which propagate in the solution like tiny tsunamis.

Their areas of inquiry span ocean, wilderness and metropolis, revealing a huge amount of information about our changing planet just by taking the time to listen.


Bookmark and Share


Thanks for a fascinating post. On a related note, there's a recent Independent piece on the positive effects of birdsong on mental health:

Dr Bird [sic!] also recommended birdsong for the elderly and for those who suffer from high levels of stress. "We have lost our connection with nature," he said, adding: "By having birdsong, it's away of connecting back, and our mental health improves when that connection has been made."

I also heard a snippet on the World Service recently about a Scandinavian city (Stockholm?) asking its citizens to nominate their favourite acoustics spots in the region. A great idea to promote acoustic appreciation, but damned if I can find a reference to it... anyone?

Posted by: Gyrus on 21 Jan 07

i [quietly] echo the sentiments gyrus posted. very interesting stuff. reading up on the one square inch

Posted by: Josh on 21 Jan 07

Fun to read this. I was pondering this out loud to a friend a few years ago when I lived in a noisy Oakland neighborhood. I could swear the birds were learning common time and the 12-tone scale.

Posted by: David Lucas on 23 Jan 07

I attended the WorldChanging book tour event at the Tattered Cover in Denver and enjoyed meeting the WC team; thanks again for this important work. I bought the excellent book, but, progressive as it is, I was disappointed that the index contains no entries for "noise" or "soundscape". (:-(

Re: One Square Inch of Silence, it was fun to virtually visit that area using the powerful, invaluable - and free - Google Earth viewing program (just enter the coordinates: 47° 51.959N, 123° 52.221W; note, too, the "US National Parks" layer under "Parks and Recreation Areas"). I commend Gordon Hempton for pushing the Park Service to protect the soundscape in the national parks.

In Feb. 2003, the University of Colorado in Boulder hosted an important and well-attended multi-day event, "The Silence of the Lands: Noise and Our National Parks", co-sponsored by the CU Natural Resources Law Center, the university's Center of the American West and the National Park Service. Attendance included the Air Force and other noise producers (helicopter and snowmobile people), the National Park Service Deputy Director from DC (a former Rocky Mountain National Park superintendent), a former congressman, and folks from a host of environmental groups (Sierra Club, Greater Yellowstone Coalition, National Parks Conservation Association). The symposium covered a lot of territory, so to speak, and, I dare say, was attended by a lot of The Right People - a landmark event. I suggest a follow-up event would be very worthwhile.

BTW, the National Association for Interpretation's Jan/Feb. 2007 issue of their Legacy magazine has several articles under this topic: Using All the Senses - The Importance of Sound in the Interpretive Experience.

Posted by: Doug Grinbergs on 25 Jan 07

A short follow-up with some additional important links for interested and concerned folks who may care to learn more about the issues and help turn down the noise:

National Park Service Natural Sounds Center (based in Fort Collins, Colorado)

Grand Canyon Trust's website features the outrageous history of air tour overflights at Grand Canyon and the government's decades-long failure to fix the problems; expect this issue to get much more attention in the coming year or so.

Some U.S. anti-noise groups:
Noise Free America
Noise Pollution Clearinghouse

12th Annual International Noise Awareness Day: April 25, 2007

Thanks for your attention and interest.

Posted by: Doug Grinbergs on 8 Feb 07



MESSAGE (optional):

Search Worldchanging

Worldchanging Newsletter Get good news for a change —
Click here to sign up!


Website Design by Eben Design | Logo Design by Egg Hosting | Hosted by Amazon AWS | Problems with the site? Send email to tech /at/
Architecture for Humanity - all rights reserved except where otherwise indicated.

Find_us_on_facebook_badge.gif twitter-logo.jpg