If you're tired of getting additional information, you can just close your eyes, get some sleep. But earlids, covering of the ears, never evolved. Not once do we find it, even in the fossil records. Because while we let our eyes relax, our ears are still hearing. And that's why alarm clocks work and wake us up. We still gather information. Every animal is gathering information 24/7. So I like to think of acoustic ecologists as people who are trying to become better listeners, 24/7.

How are we going to know what sounds are important before we've even heard those sounds? It's an absurd question. The only thing we can say is that we're going to base it on our past experience. In other words, modern listening doesn't inform us of anything new. It simply keeps us in the past.

What visual information does is it creates priorities. You cannot know with certainty what lies behind something else. There are very few transparent materials in the natural world or the built environment. And so we deal with things superficially, and we deal with what's in front of us, not what's behind our head that we can't see, or to the left or the right. Visualists are often linear and timeline-oriented, whereas the natural condition and the natural way of problem-solving throughout evolution is to be multitasking.

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.

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.

You don't really need to engage your visual sense, because the natural wiring of the human psyche is to monitor the environment through sound, not through sight. But we're convinced through modern conditions that we have to look at everything, and that creates stress in our life, because we're trying to solve problems in ways that are much more time consuming, not efficient, and not fun.

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.