EARS & WAVES

← Sound phenomena

Play a theremin.

The instrument you play without touching it. Hold and move across the pad for pitch, up and down for volume, and hear the voice of 1950s science fiction.

Now playing Deep sleep

Play it, or listen

Hold the pad and move: left to right is low to high, bottom to top is soft to loud; let go and it falls silent. Or tap an example to hear it played, and again to pause. The spectrogram draws the melody as you play.

How a theremin works

A real theremin has two antennas and is played without touching it. The player’s hands act as part of two electrical circuits: moving one hand towards the upright rod raises the pitch, moving the other towards the loop lowers the volume. Inside, two high-frequency oscillators beat against each other, and their difference is the tone you hear.

With no frets or keys, every note is found by ear and every move glides, which gives the theremin its singing, eerie voice. The pad here plays a simulated theremin: across for pitch, from about 130 to 1300 Hz, and up and down for volume.

Facts that often get mixed up

  • Léon Theremin, a Russian physicist, invented it around 1920 while working on sensors that detect nearness; he toured it and patented it in the United States in 1928.
  • The Beach Boys’ “Good Vibrations” does not use a theremin but an Electro-Theremin, a slide-controlled instrument that sounds similar.
  • Its eerie glide made it the sound of science fiction and suspense: The Day the Earth Stood Still (1951) and Hitchcock’s Spellbound (1945) both feature it.
  • Clara Rockmore, its great virtuoso, showed it could play classical music with precise pitch, using hand positions she developed.
Real thereminThis pad
PitchHand near the vertical antennaLeft to right
VolumeHand near the loop antennaBottom to top
SilenceHand at the loopLet go
RangeSeveral octavesAbout 130–1300 Hz
How do you play a theremin?

Without touching it: one hand near the upright antenna sets the pitch, the other near the loop sets the volume. Here, hold the pad and move across for pitch and up and down for volume.

Why is the theremin so hard to play?

There are no frets, keys or markings: every note is found by ear in empty air, and the smallest move of the hand changes the pitch.

What music uses a theremin?

Classic science-fiction and thriller scores, concert pieces written for it, and rock and pop from Led Zeppelin to modern film music.

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.

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.

White

0 dB / octave

Equal energy at every frequency. Because we hear in octaves, it sounds bright and hissy — the classic "TV static".

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
20,000Hz

Can you still hear it?

Hearing age test →

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.

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.
Deep sleep