I have just entered one of the few remaining truly quiet public places on earth. It's a silence so deep and powerful it almost has fragrance. Metaphors spring forth. An eel swimming in oil. Dew falling on a rose. An Iroquois canoe gliding downstream.

I speak, of course, of Amtrak's Quiet Car.

We pull out of Philadelphia's 30th Street Station, and the silence becomes threaded with the faint, pleasing pocketa-pocketa-pocketa of the train wheels. I have returned from a tense, day-long meeting, and I welcome this opportunity to oil a squeaky day. I sit back and allow the silence to breathe, like a good red wine.

Bam!  Bang!  Bark!  Beep!  Blare!  Blast!  Boom!  Buzz!  Cackle!  Clang!  Clap!  Clink!  Crackle!  Crash!  Creak!  Drone!  Drum!  Grate!  Grind!  Hiss!  Honk!  Howl!  Hum!  Knock!  Ping!  Pop!  Pow!  Rat-Tat-Tat!  Rattle!  Ring!  Roar!  Rumble!  Scream!  Screech!  Shout!  Shriek!  Smash!  Snap!  Splat!  Squawk!  Squeal!  Thud!  Thump!  Toot!  Twang!  V-rrr-oooom…!

Listen up!  Noise is the enemy.  Everyday we are experiencing a sonic attack on our minds and bodies.  Noise is an effluvium — odorless, tasteless, invisible — of our racket-ridden world.

No noise is good noise.  There is no safe level of noise.  A prolonged exposure to a moderate sound can be more dangerous than a short burst of extremely loud sound.  Noise affects not just our ears, but our hearts, our arteries, and our stomachs.  It makes us irritable and alters our dreams.  Noise invades our privacy, for a single person with a cell phone has the awesome power to ruin the peace and quiet of hundreds of others.  Small wonder that the words "noise" and "nausea" have the same Latin root.

Noise is a lot worse than it used to be.  The sounds of the past were less intense, less frequent, and reached fewer ears. The chief culprit is the mechanization of our environment. The fact that the average older American has difficulty hearing is not the result of mere age;  it is the result of having lived so long in a noisy world.  People in less developed areas of the world — where there is no heavy traffic, no lawn mowers, no sirens — do not experience the same decline in hearing that most of us view as part of growing old.

Pocketa-pocketa-pocketa. As we leave Paoli, I open my laptop and go online, aware I am making only the faintest plik-plik-plik as I tap the keys. No one seems to notice. I open the AARP website and find this after a search.

"Hearing loss is America's silent epidemic. It can have a more negative impact on the quality of life than obesity, diabetes, strokes, or even cancer. … Hearing loss is associated with an increased risk of dementia, falls, and depression. It is also a serious contributing factor to social isolation and loneliness, and has been linked to poorer job performance and lower salaries, as well."

Noise can be difficult to define.  One man's symphony is another's cacophony. A barking dog may be reassuring to its owner, annoying to its neighbor.  Noise is any unwanted sound.  Or to paraphrase Justice Stewart on pornography, noise is hard to define, but you know it when you hear it.

Pocketa-pocketa-pocketa. As we glide through Pennsylvania farmland — lush, squared-off acreage of rich and generative soil running to the horizon — I learn on Google that Amtrak began the Quiet Car concept in 1999 on a Philadelphia-Washington run in response to passengers seeking relief from Cell Hell. The experiment was a great success, and the concept was extended to most trains.

Today Quiet Car riders are asked to conduct conversations in subdued voices, refrain from using cell phones, and lower or mute the volume on such devices as games. Amtrak put the mute into the commute, and established an important principle: You have the right to a little peace and quiet when you travel.

Noise has gotten a late start compared to other forms of pollution, both in terms of regulation and public opinion. According to George Prochnik, author of Pursuit of Silence, "If you compare the level of awareness about air quality or greenhouse gas emissions to noise, I think we are still at an early stage."

Yet noise is damaging our bodies and minds and robbing us of meaningful human interaction and thought.  It's time to speak up, soft and clear, on the noise issue.  If we can have smoke-free areas, we can have noise-free areas, too. Thank you, Amtrak.

I step from the train at Elizabethtown Station. Walking to my car, an ambulance rushes by, snapping its whip of sound. Nearby a jackhammer rains blows on my skeleton. As I wait for a traffic light to change, a convertible pulls up beside me, and a telephone erupts in a ring that would pain Quasimodo.

This car is not the Quiet Car.

William Ecenbarger, a former Inquirer staffer, is a freelance writer.  william.ecenbarger@gmail.com