I blogged earlier about how chronic, even low-level noise boosts levels, which in turn trigger health problems such as hypertension. My awareness of this in my own life caused me recently to embark on a year-long search for silence, both as an antidote to noise and stress, and as a way to change my life generally.

Silence, of course, is the utter absence of input to the hearing system. Thinking about auditory silence got me reflecting on other inputs, and how important it might be to achieve respite from the constant bombardment of information from every quarter: billboards, video, road rage, Jerry Springer, Gap ads. Facebook updates, cellphone calls. Spam, Tweets, Digg; alarms and interruptions of all stripes.

In my search for auditory silence I looked everywhere I could think of. I went 1.6 miles underground to the lowest levels of a nickel mine in northern Ontario. I visited a Trappist monastery in Burgundy. I spent time in complete darkness inside the most perfectly soundproof chamber in the world, in Minneapolis. One of the greatest silences I ever experienced was in the mountains of the southern Sahara, near the border between Algeria and Niger.

I won't tell you if I found perfect silence: you'll have to read the book to find out. But I learned something crucial in the process of looking: that the absence of noise correlated to the absence of other types of unwanted input. Put simply, places that were quiet in terms of auditory noise were low in other kinds of noise as well. You don't get Tweeted in the southern Sahara, there are no billboards in the depths of a nickel mine, Trappist cloisters have no TV, you see and feel nothing in a darkened soundproof chamber. On Cape Cod, where I used to live, you see landscape and feel beachgrass when it is quiet, but pinewoods and spartina are gentle; they do not attack you, they are low level actors.

The link between low sound and low levels of other kinds of input is to some extent a function of how noise, in Western society, is considered a symptom of healthy economic activity. We want noise, loud and constant, because it tells us our machines are running, our cash registers are in use, our video feeds are hot, our colleagues surround us. We tolerate it, even when it drives us mad, because we think we need such activity to survive. Silence, in that worldview, is bad. It's a metaphor of malfunction, as Scollon says.

But here we make a serious mistake. The opposite is the case. Noise kills, excessive input does real damage. Information overload clogs our ability to function effectively. Remember the incident in October, 2009, when a Northwest Airtlines jet overshot Minneapolis and kept flying for an hour while the pilots interacted with a computer program? This is what happens when we do not have the time, or the power, to cut off input, to achieve peace-aural, visual, tactile-for a given period of time. Often we are so wrapped up in our culture of all-spectrum noise that we lack even the will to escape it. The website Interruptions.net lists over 800 independent studies demonstrating how information overload, usually inflicted by computers, slashes , efficiency, and safety in environments as diverse as a call center office, a hospital emergency room. And David Shenk, the journalist who coined the term "data smog," cites studies correlating information overload to the same kinds of stress and cardiac problems caused by auditory noise only.

People can retain roughly 7 chunks of information in . Posit a person working on a complicated computer file, fielding two emails from different people on different subjects, staying aware of colleagues, listening to music, thinking of dinner, and you've already got double or triple the number of chunks he or she can successfully retain and process. Driving with my kids through Harvard Square-watching out for six Massachusetts drivers, three pedestrians, two potholes, traffic lights, what my daughter's talking about, what NPR is reporting-my thinking abilities, already far from stellar, are dangerously gummed up by input. And that makes me tense, even angry. I honk back, I curse, and gun the engine to make the light.

But I don't want , I can feel how much stress this kind of life causes. Release is what I'm truly craving here, and release comes from emptiness. The emptiness of silence, of landscapes, of closed eyes, of down in a dark, quiet room. The drop in tension that happens when we take a vacation somewhere calm, the instant of zero gravity during , the psychic leap of a good joke when it flips the world on its head for a splinter of a second. Such void cuts off the fascist flow of constant information, and allows us to recalibrate. To think better. To question, for a second, our baseline.

It is really, really important to do that. Human rests on a three-part process: (1) off previous assumptions, (2) coming up with an idea, (3) testing if the idea works. The first part of the process means being able to cut off all input, especially input we don't want. But how can you do that in a society that relies on transmitting, 24/7, at maximum volume into your eyes, ears, tastebuds and touch, a constant and vicious overdose of mostly useless data?

(In the next post: Building silence into our lives: A how-to guide)