A matcha latte in a speckled ceramic cup, its surface rippling with sound
The science, in plain words

Everything is vibrating

Sound is vibration. Most of it happens too low, too high or too quietly for our ears. Here is the whole range I capture, and how I bring it into the range we can hear and feel.

Step one

What a hertz is

Tap a table and the wood wobbles back and forth, faster than the eye can see. Hertz (Hz) counts those wobbles in one second. One hertz is one wobble a second, about the pace of a lazy stroll. A hummingbird’s wings beat about 50 times a second: 50 Hz. A phone buzzing on a table wobbles about 200 times a second: 200 Hz. A thousand hertz is a kilohertz (kHz), so 20 kHz means 20,000 wobbles a second.

Faster wobbles sound higher. Slower wobbles sound lower. Pitch is speed. The unit is named after Heinrich Hertz, who proved in the 1880s that invisible waves are real.

Step two

What our ears hear

People hear from about 20 Hz to about 20,000 Hz. Children hear the very top; most grown-ups lose the highest notes over the years. Below 20 Hz we stop hearing and start feeling: a truck idling outside, the floor during a bass drop, the ground in an earthquake. Above 20,000 Hz is a world we have never heard: dog whistles, bat calls, and plants clicking when they’re thirsty.

Step three

The whole range I capture

These sensors feel vibration from about one wobble a second up to around a million a second. Our ears cover a sliver of that, in the middle. Here is what lives where.

The whole range, from 1 to about a million vibrations a second A vertical scale. The low end is felt, the middle is heard, the top nobody hears. Landmarks from someone strolling past the table to about the top of what these sensors feel. FEEL HEAR BEYOND what these sensors feel: 1 Hz to about a million 10 100 1,000 10,000 100,000 Someone strolling past the table one step a second, felt through the floor An earthquake’s roll mostly under 20 Hz A washing machine on spin 13 to 20 Hz, which is why the floor shakes A cat’s purr 25 to 150 Hz: felt as much as heard The bass drop at a show 30 to 60 Hz. The floor does the hearing A hummingbird’s wings about 50 beats a second: that’s the hum A phone buzzing on the table 150 to 300 Hz, and the whole table joins in A spoon tapped on a latte cup a few thousand Hz, a clear ring The highest key on a piano 4,186 Hz The viral hearing-test tone about 17,000 Hz. It fades through our twenties The top of human hearing 20,000 Hz as a kid, lower every decade A dog whistle 23,000 to 54,000 Hz. Silent to us, loud to the dog Thirsty plants, clicking (yes, really) 20,000 to 150,000 Hz, recorded in 2023 Bats, calling in the dark 20,000 to 120,000 Hz. They hear the echoes Dolphins, clicking to each other up to about 150,000 Hz A wax moth, the best ears on Earth 300,000 Hz A crack growing inside steel how engineers find a crack in a bridge early A bubble a tenth of a hair wide, ringing about a million Hz, too fast for any ear About the top of what these sensors feel around a million Hz. Nothing alive hears here.
The scale is logarithmic: every step up the ladder is ten times faster.
Step four

How I bring it to the world

  1. Turn it up

    A sensor on the table picks up a vibration that never made it into the air. I make it louder, like enlarging a photo.

  2. Slow it down

    Play a sound slower and every wobble takes longer, so the pitch drops. Four times slower is two octaves lower. A click at 100,000 Hz, slowed ten times, becomes a 10,000 Hz click anyone can hear. That is how bat detectors work, and how scientists let people hear plants.

  3. Shift it

    Sometimes I move a sound down the ladder without slowing it, like singing a song in a lower key. A whisper at 300,000 Hz can become a note. A sway at 1 Hz can become a hum.

  4. Feel it

    For the low end I use haptic devices: shakers that move a bench, a plate or the floor. Below 20 Hz, hearing hands over to feeling, the way a passing truck or a bass drop comes up through the floor.

Step five

I don’t know what I discovered until later

At the table I can see the sensors, the camera and the coffee. I can’t hear most of what they are feeling; no one can. Weeks later, in post-production, I slow it down, shift it and turn it up, and a ring, a crackle or a hum shows up that nobody at the table knew was there. That surprise is one tiny piece of this entire project.

Come make some tiny sounds

About an hour at a Portland café. Your latte, matcha, or pastry is on me.

Count Me In
Count Me In Your latte, matcha, or pastry is on me