All Sound is Vibration by Julia Knox

Photo by Ralph (Ravi) Kayden

All Sound is Vibration

A Sound Wave is Made of Pressure

All sound is vibration, and a sound wave is made of pressure.

What do you hear?

Perhaps it's a memory. Perhaps it’s, “I believe in you. I’m proud of you. I’m so glad you made it.” Perhaps it’s “You’re not good enough. You don’t belong here. Why are you here?”

Perhaps it’s both.

All sound is vibration, and a sound wave is made of pressure. Sound is a function of time.

The car honks at regularly scheduled intervals, I could fool myself into finding it melodic. Today, my accessory is the decibel, it’s the ambiance, I’ve accepted it: It’s part of my environment. My time here is short.

All sound is vibration and a sound wave is made of pressure. Sound is a function of time, but it is also a function of space.

As you go about your day, what do you listen to?

Perhaps it’s a memory. Perhaps it’s an inner voice. Perhaps a siren, perhaps your family, perhaps it’s those with whom you work.

Perhaps you find you do not listen because you have not heard.

All sound is vibration, and a sound wave is made of pressure. Sound is a function of time, but it is also a function of space. Where the wave travels: This is important.

During the day, the sound decreases with height. In the mornings, when I take the elevator to the 16th floor of the lab, I move away from the noise of everyday life.

All sound is vibration, and a sound wave is made of pressure. Sound is a function of time, but it is also a function of space. Where the wave travels: This is important. During the day, the warm air close to the earth bends the sound wave upward, resulting in a “shadow zone.”

Is the sound simply moving more slowly up here?

All sound is vibration, and a sound wave is made of pressure. Sound is a function of time, but it is also a function of space. Where the wave travels: This is important. During the day, the warm air close to the earth bends the sound wave upward, resulting in a “shadow zone.” Due to the shadow zone, you can see many sources of sound, but you cannot perceive them.

The same man asks for change, repeating the same line, at the 168th Street Station. The warble of the siren, spanning nearly the entire audible frequency spectrum, passes us by before careening onto Broadway. The EMS truck beeps as it backs into its space adjacent to the hospital entrance. In the lab, I hear only the hum of the freezers, the soft voices of my lab-mates, and the elegant rhythm of the piano playing through my headphones. Am I in the shadow zone?

All sound is vibration, and a sound wave is made of pressure. Sound is a function of time, but it is also a function of space. Where the wave travels: This is important. During the day, the warm air close to the earth bends the sound wave upward, resulting in a “shadow zone.” Due to the shadow zone, you can see many sources of sound, but you cannot perceive them. In the evenings, when the earth cools, and temperature inversion causes sound waves to “bend,” or refract, downwards. At night, when the Earth begins to cool, we can hear across vast distances.

Who is speaking to us? Or what? Are we there to listen? When we speak, can we be heard?

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The Author

Julia Knox is a research scientist and candidate in Narrative Medicine in the Columbia Department of Medical Humanities and Ethics, and fellow at the Precision Medicine Ethics, Politics, Culture Project at Columbia's Center for Social Difference. She is interested in how personal data takes narrative form in our society.

Julia Knox, Brooklyn, NY