Diane Ackerman

But if you lose your sense of hearing, a crucial thread dissolves and you lose track of life’s logic. You become cut off from the daily commerce of the world, as if you were a root buried beneath the soil

Sounds thicken the sensory stew of our lives, and we depend on them to help us interpret, communicate with, and express the world around us

People want certain foods (potato chips, pretzels, cereals, and the like) to crunch; noise is an important ingredient in the marketing of such foods

Then, wishing one another well, we clink our glasses together because sound is the only sense missing from our full enjoyment of the wine

What we call “sound” is really an onrushing, cresting, and withdrawing wave of air molecules that begins with the movement of any object, however large or small, and ripples out in all directions

begin trembling, too, and so on. Waves of sound roll like tides to our ears, where they make the eardrum vibrate; this in turn moves three colorfully named bones (the hammer, the anvil, and the stirrup), the tiniest bones in the body. Although the cavity they sit in is only about a third of an inch wide and a sixth of an inch deep, the air trapped there by blocked Eustachian tubes is what gives scuba divers and airplane passengers such grief when the air pressure changes

When the fluid vibrates, the hairs move, exciting the nerve cells, and they send their information to the brain

Its job is partly spatial. A gently swishing field of grain that seems to surround one in an earthy whisper doesn’t have the urgency of a panther growling behind and to the right.

There is a geographical quality to listening

But it all begins with quivering molecules of air, each being jostled into the next, like a crowd pressing forward into a subway. The waves they set up have a certain frequency (the number of compressions and relaxations in each second), which we hear as pitch: The greater the frequency, the higher pitched we find the sound