Whenever you're in a natural system and you're making sound, you are putting yourself at risk. As you go up the evolutionary ladder, from insects to frogs to birds and on up into mammals, the higher intelligence recognizes that when you vocalize, you put yourself at risk. So mammals generally vocalize or make noise much more rarely than, let's say, insects or frogs. And when they do, and put themselves at risk, it has to be worth the risk, and have true meaning, such as signaling during a hunting party, calling in prey, some religious or spiritual ceremony, something like that.

Quiet is the element of discerning what is essential.

The earth has continued to change, from rapid climatic changes that have caused the glaciers and the ice sheets to basically bulldoze the landscape and cause species compression in the tropics and cause mass species extinction - you know, all these huge changes. In terms of evolution, every species is doomed to eventual extinction. The natural world is constantly changing. So, to deal with "environmental problems," in quotes, totally misses the issue. That is not the way we want to define our problem if we're going to find our solution.

Not only does the modern person often think that sight is more important than sound - there's no objective evidence to indicate that. Many people, even audiologists who study the science of human speech and hearing, have assumed for a long time that the human ear evolved to hear the human voice, rather than the voice changing to fit the human ear. And the human ear is actually not a perfect match if we map its sensitivity to the different frequencies in the human range of hearing; it's an unequal curve, it's kind of a wavy line.

We think the problem is out there, when the problem is really in here - who we are and how we experience the world around us. The acoustic ecologist listens, as the primary sense, to the world around us, and I believe that they have a significant contribution to make to all environmental groups who think that they're solving environmental problems, when we're actually all on a spiritual pilgrimage.

I used to hate the urban environment and the urban din. But I realize now that it's really not that much different than living next to a waterfall for wildlife. Most wildlife - unless they're specifically adapted - avoid being around a waterfall or whitewater streams and rivers because it jams their sense of surveillance. They are more vulnerable, and their message loses intelligibility. Now, the ouzel is able to overcome that in various ways. Back to the urban environment, we're talking and delivering messages as if we weren't next to a waterfall, and that's a problem.

Noise pollution is basically defined as the presence of simple information that makes it impossible to hear all the other more delicate - and often more important - information. Noise pollution creates, if you will, dumb environments. Our industrial areas, many of our downtown urban areas, are dumb acoustic environments. Very simple, very loud, often unhealthy.