Speed of Sound in Air, Water and Steel — hear it

Hear how fast sound travels

Tap an example to play it, and again to pause. The picture races the sound through each material, in real time. With the slider, set how far away the lightning is and count the seconds yourself.

Why sound travels at different speeds

Sound is a push passed from particle to particle. How fast it goes depends on how stiff the material is and how heavy its particles are. Water is far denser than air but very much harder to squeeze, so sound runs through it more than four times faster; steel is stiffer still. In light helium sound is almost three times faster than in air, and in heavy sulfur hexafluoride it is much slower.

In air it also depends on temperature: about 331 m/s at 0 °C, 343 m/s at 20 °C, a little more for each degree. That is enough to measure distances by ear. Light arrives almost at once, so the seconds between a flash of lightning and its thunder, divided by three, give the distance in kilometres.

Facts that often get mixed up

Helium does not raise the pitch of your voice: your vocal folds vibrate just as fast. Sound moving faster shifts the resonances of your throat and mouth upwards, which changes the colour of the voice.
Count the seconds from flash to thunder and divide by three for kilometres (by five for miles); if it is under 30 seconds, the storm is close enough to be dangerous.
In 1826 Colladon and Sturm measured sound in water on Lake Geneva: a bell struck under water at the same moment as a flash of gunpowder, timed from a boat across the lake.
Sound is faster in water than in air even though water is heavier, because it is so much harder to compress.

Material	Speed of sound	1 km takes
Air at 0 °C	331 m/s	3.0 s
Air at 20 °C	343 m/s	2.9 s
Helium	1007 m/s	1.0 s
Sulfur hexafluoride	134 m/s	7.5 s
Water	1480 m/s	0.68 s
Glass	about 4500–5600 m/s	about 0.2 s
Steel	about 5000–6000 m/s	about 0.17 s

How fast is the speed of sound?

In air at 20 °C, about 343 metres a second, or 1235 km/h. In water it is about 1480 m/s, and in steel about 5000–6000 m/s.

How far away is the lightning?

Count the seconds between the flash and the thunder and divide by three: that is the distance in kilometres. Six seconds is about 2 km.

Why does sound travel faster in water than in air?

Speed depends on stiffness as well as density. Water is about 800 times denser than air but far stiffer, so overall sound moves more than four times faster.

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

Silence during breaks

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

Noise volume

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

Tone volume

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.

Speed of sound.