Quiet is the element of discerning what is essential.

"Acoustic ecologist" is basically a fancy name for someone who tries to become a better listener. Not just listening to those thoughts, ideas, and productions of human intention, but listening to places - whether it's an urban environment, residential, industrial, or even the farthest corner of the world, in one of our last great quiet places where we can listen to the pure sounds of nature without any human-caused noise intrusions.

Often how you define the problem will determine whether or not you're able to find a real solution.

I believe that our distant nomadic ancestors came forward and survived because they could hear distant, faint birdsong as an acoustic navigational beacon, if you will, and by moving toward the birdsong, they were able to find places with shelter, food, and water, and a prosperous growing region. Indeed, birdsong is the number one indicator of habitats prosperous to humans.

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.

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.

The most sensitive frequencies are at the resonant frequencies of the auditory canal. In other words, the ear has shaped itself to naturally amplify certain bandwidth. And that corresponds to sounds in that bandwidth that were most important to our evolving ancestors to hear, in order to survive. And it doesn't match the human voice. It matches birdsong.