The Urban Ear

I never slept better than when I lived in a walk-up on Avenue of the Americas, just below Houston Street. The silence of the provinces where I live now, in Amherst, Mass., keeps me up at night, but in New York I was lulled into deep sleep by the endless roar of traffic and the humming music of the C train, punctuated by laughter and boisterous argument.

At least to some ears, city sounds are incredibly soothing. The wealth of sounds that come with too much humanity rooted in too little geography tells us better than anything else that we are in a wonderfully dense urban environment. Each neighborhood has its own particular aural ecology: varieties of sound, quality of echoes, differing dynamic ranges that ebb and flow throughout the day.

We are far better at recognizing our visual environment, but all of us, if blindfolded, would know by the sounds that we were home. The murmurs of sleepy Carroll Gardens sound far different from the bustle and buzz on the sidewalks of first-generation Jackson Heights.

Some city sounds are not so comforting. There is the half-heard sidewalk exchange that at first seems spirited but then sounds violent. There is that screech of brakes that seems especially desperate or, worse, ends not in silence and a "phew" but in a crash. Sometimes, the sound is not only unsettling, but in its size and unfamiliarity, terrifying.

That is the kind of sound that roared through Midtown on Wednesday, just before 6 p.m. Workers getting ready to head home during the afternoon rush heard powerful rumblings that exploded into what people variously described as a roar like Niagara Falls, a volcano erupting, a hailstorm that pelted skyscrapers with metal fragments.

Although the roar turned out to be the explosion of a steam pipe, the behavior of New Yorkers was much the same as it was in response to a far different noise, on 9/11. People busy with their lives instinctively stopped in their tracks and looked up because this particular roar, such a common noise in New York, was not just exceedingly loud, but fundamentally, and awfully, out of place.

The deer in the forest instantly knows the difference between leaves crunching underneath a raccoon and leaves crunching underneath a pair of Timberlands. Though humans' hearing is not as acute as that of many animals, we have an ability unique among creatures to hear and interpret multiple sounds and instantaneously sort them, hearing in detail the ones we care about and suppressing the ones we don't.

Like a photographer who focuses in close on the face of a companion, and then shifts focus to the store across the street, we can catch the conversation of the people next to us, then hear the voice of someone yelling from across the street, respond to the honk of a horn, all while pushing out of audible focus the background rush of thousands of cars passing, dogs barking and subways rumbling by.

This sonic editing is no mean feat. Think of the auditory stew New Yorkers place themselves in each day as they wake from the little night music of the city. The shuffling sounds of other New Yorkers preparing themselves for the day, the clack of feet on apartment-building stairs or the groaning of elevators, accelerate as the minutes head toward 9 a.m.

We enter the street as if we are stepping into a river, pulled along by the staccato of feet, and immediacy of traffic sounds, before heading underground to be deafened by the coming growl of our train. Increasingly many New Yorkers tune out the city by tuning in to iPods and cellphones, adding an extra layer of personal sound to the public sound of the city.

Yet through it all, the democratic ear takes it all in — there is no neat flap of skin like the eyelid to turn the sound on or off. Never was there so overworked an organ as a New York eardrum.

I heard about Wednesday's steam blast on Lexington Avenue as I was headed to Boston to see the Edward Hopper exhibition at the Museum of Fine Arts.

Hopper's images are famously quiet. A lone man reading a paper under a street lamp at night; a solitary woman in an Automat; another woman staring out the window of an apartment building. Yet Hopper's paintings are about not the absence of sound but the quiet moments and places away from the heart of the city's soundstage.

WE love "Early Sunday Morning," for example, an iconic image of low storefronts on Seventh Avenue from 1930, because we can almost hear the sounds that will be back on Monday — cars and people passing, stores being opened, wares being hawked. Hopper's figures look, for comfort, out to the sounds of the city.

In 1950, the composer John Cage moved into a tenement building on Monroe Street on the Lower East Side and opened his windows to mingle the city's music and his own. In came the sounds of this immigrant neighborhood and the still-vibrant industrial waterfront nearby. It was here that he composed some of his most famous works, like "Imaginary Landscape IV" and "4' 33" " — all drawing on the indeterminate music made from his neighborhood.

A few years after Cage left (his neighborhood was urban renewed out of existence by Robert Moses), Harry Belafonte was marching down the middle of 42nd Street, right past the future site of the steam pipe explosion on Lexington Avenue, in the 1959 sci-fi doomsday film "The World, the Flesh and the Devil," alone in the city, missing the companionship of people and the urban sounds they make.

Those who heard the jets roar on 9/11 and those who heard the "volcano" erupt from beneath the streets last Wednesday will never forget that sound. The only thing worse would have been silence.