I would say that to listen is to become aware. To become truly informed. You will discover whatever you do.

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.

The birds are already evolving, changing the way that they sing as a result of noise pollution. And we have yet to do that. We're still not communicating. We're not changing our words. We are not testing, not providing this new lexicon for noise-polluted areas.

I'm in love with Earth. I truly am. And so listening is not work, to work toward a better future. It's joy. To not be able to work toward a better future would be work. That would be tough.

Healthy areas that are richest in information are those areas in the wild where we can get all the information that's available to us within our human hearing range. The most valuable information throughout human evolution has been faint sounds. We tend to think in our modern world that if it's loud, if it grabs our attention, it's important. We get a lot of that in advertising. But in nature, it's the faintest sound that's important; it has determined, in the past of our ancestors, perhaps, if they will live or die. Faint sounds are the earliest clues of newly arriving information.

Most people think visual information is more important than aural information - like, what's this big deal about sound? And why should I bother to listen, rather than look? And here are the facts: there are blind species, in the backs of the caves, the bottoms of the oceans. It's not essential on planet Earth to be able to see, to be a species. But there are no deaf animal species. You have to be able to hear, or you won't get the information you need in order to survive.

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.