White
0 dB / octave
Equal energy at every frequency. Because we hear in octaves, it sounds bright and hissy — the classic "TV static".
Sound phenomena.
Seventeen things sound does, from a siren dropping in pitch to a tone that rises for ever. Each page plays them for you and draws what you hear.
Now playing
Deep sleep
Choose a phenomenon
Headphones help with the stereo ones, like the Haas effect and the auditory illusions.
Why sound behaves this way
Sound is a pressure wave in the air. It travels at about 343 metres a second, bounces, bends and adds up with other waves, and the ear and the brain make sense of what arrives. Many surprises come from that: a pitch that drops as a car drives past, notes that seem to climb for ever, a tone you hear that nobody plays.
Each page shows one effect with examples to play, a live picture and a few facts, so you can hear the physics and the psychology of sound for yourself.
What is the best-known sound illusion?
The Shepard tone: a sound that seems to rise or fall for ever. Film scores use it to build tension.
Why does a siren change pitch as it passes?
The Doppler effect: the waves bunch up in front of a moving source and stretch out behind it, so the pitch is higher as it comes and lower as it goes.
Is space really silent?
For our ears, yes: there is no air to carry sound. The sounds of space are radio and plasma waves turned into sound.
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.
