White
0 dB / octave
Equal energy at every frequency. Because we hear in octaves, it sounds bright and hissy — the classic "TV static".
Scary sounds in music.
Why do some notes sound calm together and others tense or frightening? Hear the intervals from the smooth octave to the tritone, the chords of film villains, and see their harmonics clash.
Now playing
Deep sleep
From smooth to scary
Tap an example to play it, and again to pause: each note plays alone first, then all together. The picture shows the notes’ harmonics: green where they meet, red where they clash and beat.
Why some notes clash
Every note carries harmonics. When two notes are in a simple ratio, like 2:1 (an octave) or 3:2 (a fifth), many of their harmonics land on exactly the same frequencies and the sound is smooth: consonance. When the ratio is complicated, harmonics land close together but not on each other, and beat 20 to 60 times a second: a roughness we hear as tension, dissonance.
Film composers use exactly this. Semitones rubbing together, clusters of neighbouring notes, the tritone and the diminished seventh keep the ear waiting for a resolution that does not come. How tense a chord feels is also learned: people raised without Western music often do not prefer consonance at all.
Facts that often get mixed up
- The tritone was nicknamed “diabolus in musica”, the devil in music, by later theorists; the story that the Church banned it has no evidence behind it.
- The tritone is not only scary: it opens “Maria” from West Side Story, the riff of Black Sabbath’s “Black Sabbath” and Hendrix’s “Purple Haze”.
- The shark in Jaws (1975) arrives on two low notes a semitone apart, and the shower scene in Psycho (1960) screams with dissonant violin stabs.
- In 2016 a study of the Tsimané in Bolivia, who hear little Western music, found they liked dissonant chords as much as consonant ones: part of what sounds “scary” is learned.
| Interval | Ratio | How it sounds |
|---|---|---|
| Octave | 2:1 | Smoothest: the same note, higher |
| Perfect fifth | 3:2 | Open, stable |
| Major third | 5:4 | Bright, warm |
| Minor third | 6:5 | Darker, sad |
| Major second | 9:8 | Mildly tense |
| Tritone | ≈ 7:5 (half an octave) | Unstable, eerie |
| Minor second | 16:15 | Harsh, clashing |
What is the difference between consonance and dissonance?
Consonant intervals have simple frequency ratios, so their harmonics coincide and they sound smooth. Dissonant intervals have complex ratios, so their harmonics nearly meet and beat, which we hear as roughness and tension.
Why is the tritone called the devil’s interval?
It splits the octave exactly in half and does not sit comfortably in a key, so it sounds unstable. Theorists nicknamed it “diabolus in musica”; there was no official ban.
Why do horror movies sound scary?
They lean on dissonance and suspense: semitones and clusters that rub, tritones and diminished chords that do not resolve, and sudden shrieking stabs or slow rumbles that grow.
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.
