White
0 dB / octave
Equal energy at every frequency. Because we hear in octaves, it sounds bright and hissy — the classic "TV static".
Sound resonance.
Everything has notes it likes to ring at. Hear a wine glass sing, a bottle hum, a sweep that booms as it meets a resonance, and a piano answer a voice.
Now playing
Deep sleep
Listen to things ring
Tap an example to play it, and again to pause. In the sweep, listen for the moment the tone suddenly swells: that is the resonance, and the live picture shows it jump.
How resonance works
Tap a glass, a string or the air in a bottle and it rings at its own natural frequencies, the ones its size, shape and stiffness allow. Push it at one of those frequencies and every push arrives just in time to add to the last, like pushing a swing: the motion grows far larger than any single push could make.
That is why a rubbed glass sings: a wet finger sticks and slips in time with the glass. The air in a bottle springs in and out of its neck at one pitch, as a Helmholtz resonator. And with the dampers raised, a piano’s strings pick out the notes in a voice and ring them back.
Facts that often get mixed up
- A voice can break a wine glass, but only a thin crystal one, with a very loud note held right at its resonance. MythBusters did it in 2005 with the singer Jaime Vendera.
- The Tacoma Narrows Bridge did not fall in 1940 because the wind matched its resonance: it was aeroelastic flutter, the bridge’s own twisting drawing energy from a steady wind.
- Soldiers break step on bridges for a reason: in 1831 the Broughton Suspension Bridge near Manchester collapsed under troops marching in step.
- London’s Millennium Bridge swayed on its opening days in 2000: walkers fell into step with the sway and pushed it further. It closed for almost two years to be fixed.
| What rings | Its pitch | |
|---|---|---|
| Wine glass | The bowl, bending in and out | Usually 400 to 900 Hz |
| Bottle | The air inside, springing through the neck | About 100 to 300 Hz; lower the emptier it is |
| String | The string and its harmonics | Whatever it is tuned to |
| A room | Standing waves between the walls | Low notes, about 30 to 200 Hz |
| Your ear canal | The air in it | About 2.5 to 4 kHz, where hearing is sharpest |
What is resonance in sound?
When something is pushed at one of its own natural frequencies, each push adds to the last and it vibrates strongly. Musical instruments are built around it.
Can you break a glass with your voice?
It has been done, but it takes a thin crystal glass, a very loud voice and a note held exactly at the glass’s pitch. Most glasses and voices will not.
Why does a bottle hum when you blow across it?
The air in the bottle acts as a spring and the air in the neck as a weight: together they ring at one note. Less water means more air and a lower note.
Mixes
Pick what you need. One tap to start, change anything and save it as your own.
Focus timer
Work in waves.
The Pomodoro rhythm: focus with calm sound in your ears, then take a real break. A soft bell marks every change, so you never watch the clock. Every fourth break is a long one.
Every fourth break is twice as long.
25:00Focus · 1 of 4
Sound while you work
Breathe
Slow your breathing down.
Follow the circle and the sound: it rises as you breathe in and falls as you breathe out. Choose a rhythm, or set your own, and pick what plays underneath.
Ready
Sound while you breathe
Noise generator
Any color of noise, from deep brown to bright violet — and everything in between.
Brown noise
Spectrum · 20 Hz – 20 kHz
Sound science
The colors of noise
Same randomness, different tilt. Each color shifts energy between low and high pitches — here is what that sounds like.
Pink
−3 dB / octave
Equal energy in every octave, so it sounds even to the ear. Steady rain, rustling leaves. A favorite for focus.
Brown
−6 dB / octave
Deep and warm, like a distant waterfall or a plane cabin. Masks voices and traffic without any hiss.
Grey
Equal-loudness curve
Shaped around how our hearing works, so every pitch seems equally loud. Balanced and soft.
Blue
+3 dB / octave
The mirror of pink: more treble than bass. Airy, crisp, like a light spray.
Violet
+6 dB / octave
Mostly treble, like hissing water. Sometimes used to mask high-pitched ringing.
Calm
Gentle tones to settle into: singing bowls, a slow warm drone, wind chimes tuned so every note fits.
Frequencies
Famous tones on pages of their own: hear them side by side, with honest facts.
Sound phenomena
How sound bends, shifts, rings and fools the ear, and why space is silent: hear it for yourself.
Nature
Rooms & travel
Animals & countryside
A purring cat, whales and dolphins, a nightingale in the dark, cowbells on a summer pasture. Wonderful in stereo.
For babies
Womb sounds are what a baby heard for nine months: a deep rush of blood flow, and the heartbeat.
Hearing and speaker tests
Check your ears, headphones and speakers, each test on a page of its own with a live picture.
Ear Age · 60 seconds
Test your ears.
Our ears lose the highest pitches first, and it starts early. Find the highest tone you can still hear and see the typical age for it.
- Headphones on, quiet room
- Set a comfortable volume on the 1 kHz tone
- Don't turn it up when a tone disappears — that's the point
Step 1 · Volume
Play the reference tone and set your volume so it's clear but comfortable. Leave it there.
Step 2 · Listen
8,000Hz
Your result
8k12k16k20k
A rough guide, not a diagnosis. Your phone, headphones and even this browser can cut the highest tones. Worried about your hearing? See an audiologist.
More ear tests
Check your headphones, find the deepest bass your setup can play, or play any pitch you like.
Headphones check
Left & right
Each ear should get its own side. It matters for 8D, binaural beats and every stereo sound here.
Headphones on, then tap a side.
Bass test
How low can you go?
Deep tones from 200 Hz down to 20 Hz, the bottom of human hearing. Mostly it tests your speakers or headphones.
200Hz
Your setup plays down to
Tone generator
Any pitch, 20 Hz – 20 kHz
Hz
Start quiet: high tones and square waves get tiring fast.
Take it to bed
An app without the app store.
Add Ears & Waves to your home screen and it opens like any app — full screen, with its own icon. Everything it needs is saved on your device, so it keeps playing on a plane, in a tent or with Wi-Fi off.
Preparing offline mode…
- Works offlineNo streaming. Sound is computed on your device, forever.
- Screen offKeeps playing with the phone locked. The timer fades it out gently.
- PrivateNo account, no ads, no cookies. Your mixes stay on your device.
