Sleep sounds
Sixteen sounds, and an honest account of what each one does
A sound does not put you to sleep. What it does is cover the noises that would otherwise keep pulling your attention back, and give a busy head something dull to hold. These pages go through each family: what it is, why it may help, who it suits, and where it falls down.
For masking a noisy street or a snoring partner, start with brown noise. For something less clinical, rain. For blocking speech specifically, white noise sits closest to the frequencies that carry a voice. In Tock you can layer four at once and save the result as a mix.
- Fall-asleep sounds
- 63Fall-asleep sounds22 recorded, the rest generated
- You can layer at once
- 4You can layer at onceSaved as a mix
- With a distance control
- 42With a distance controlFar, Near or Close
Hear one now
What a sound is actually doing while you sleep
Your hearing does not switch off at night. It is the sense that keeps working while the others stand down, which is the whole reason a dripping tap can wake you and a bright room usually cannot. A steady sound raises the background level so the difference between silence and a car door is smaller, and a smaller difference is less likely to pull you up out of a light patch.
That is masking, and it is the honest claim. Beyond it the evidence thins out quickly. Sounds that promise to deepen sleep, retune your brainwaves or move you through stages are making a much bigger claim on much weaker ground, and the page onbinaural beats goes through why.
If you want the underlying mechanics rather than the sound-by-sound tour,white, pink and brown noise sets out how the three differ in spectrum and why masking is the one benefit the evidence holds up, andwhy we generate these sounds instead of looping them covers how they are actually made.
The noise colours
Flat, broad and boring on purpose. These are the masking sounds, and the only real difference between them is where the energy sits.
- White noiseGeneratedWhite noise holds equal power in every one hertz band, which makes it the brightest of the sleep noises and the best at covering thin, sharp sounds: keys in a lock, a running tap, a voice through a wall. That same brightness is why plenty of people last about an hour before switching to pink or brown.Play a clip here
- Brown noiseGeneratedBrown noise puts almost all of its energy in the low end, dropping roughly 6 dB with every octave you climb, so it reads as a rumble or distant surf rather than a hiss. That low weight is exactly why it covers traffic, footsteps and a neighbour's bass better than white noise does, and also why it can feel like pressure if your room is already quiet.
- Pink noiseGeneratedPink noise drops about 3 dB with every octave, which works out to equal energy in every octave and is close to how a lot of natural sound is distributed, from rain to wind in trees to tyres on a wet road. It reads as a balanced hush rather than a hiss or a rumble, which is why it is usually the right thing to try before you commit to either extreme.
Weather and water
Irregular enough to hold attention, regular enough to disappear. The most popular family by a distance.
- RainfallRecordedSteady rainfall spreads its energy fairly evenly across the audible range, close enough to pink noise that it masks about as well while sounding a great deal less like a machine. The bigger variable is the surface: rain on canvas, on glass and on a car roof are three genuinely different sounds, and only one of them will suit your room.Play a clip here
- Distant stormRecordedFar-off thunder helps at the start of the night because the slow rolling swells give your attention something easy to follow while it lets go, and it hurts later because every roll is a change in level, which is exactly what surfaces a light sleeper. Tock treats it as a fall-asleep aid and fades it out after half an hour by default.
- OceanRecordedRolling surf is broadband like rain, but it breathes, cresting and receding on a cycle of about ten seconds, and a lot of people find that slow rise easier to let go of than a flat hush. The cost is that the level moves, so it masks less reliably at the quiet end of every cycle than steady noise does.Play a clip here
- StreamRecordedA small stream is mostly mid and high frequency water noise with very little below a couple of hundred hertz, so it sounds alive and close but has almost nothing to fight a passing truck with. It suits a quiet bedroom where you want an alternative to silence, not a room you are trying to defend.
- Gentle windRecordedWind is broadband noise shaped by whatever it is moving past, drifting slowly up and down in level with no rhythm your ear can lock onto, which makes it unusually easy to stop noticing. It masks gently rather than firmly, so it belongs in a wind-down more than it belongs in a fight with a busy street.
Rooms and outsides
A sound with a location attached. Useful when a flat noise feels clinical.
- FireplaceRecordedA fire is a soft broadband roar with sparse, sharp crackles laid on top, and those crackles are transients, precisely the kind of sudden sound a light sleeper surfaces for. It is one of the best wind-down sounds in the library and one of the weakest choices to leave running until morning.Play a clip here
- Night forestRecordedA night forest bed is a soft, broad rustle of leaves with occasional distant events layered into it, and the design rule that makes it work is that none of those events should ever be identifiable. A sound you can name is a sound you then lie there waiting to hear again, which is the exact opposite of falling asleep.
- CricketsRecordedA field of crickets is not one insect but dozens slightly out of phase with each other, and that stagger is what turns a repeating chirp into a steady high shimmer you can drift on. It lives almost entirely above 2 kHz, so it covers thin, sharp sounds well and does nothing whatsoever about traffic.
- Late cafeGeneratedA cafe bed works because a room with people in it reads as safe, and it only keeps working while none of the voices are intelligible. The moment you can pick out a word you start following it, and following language is the opposite of falling asleep, which is why Tock generates the murmur instead of recording a real room.
Machines and tones
The ones people either swear by or cannot stand. Worth trying once before you decide.
- FanRecordedA fan makes broadband noise from air turbulence plus a very quiet periodic thump from the blades, sitting somewhere between pink and brown in balance, which is why so many people sleep to one without ever calling it white noise. Tock uses a recording of an actual fan rather than generating it, because that blade rhythm is the thing that makes it read as a fan at all.Play a clip here
- Sleeper trainGeneratedA sleeper train bed is a low broadband rumble with a slow, regular rail rhythm over it and the closed-in quality of a cabin, and that combination masks well while giving your attention something gentle to rest on. The rhythm is also the catch: a regular pattern is something you can start tracking again if you surface at 3am.
- PianoRecordedSlow piano gives your attention somewhere pleasant to go while you are letting go of the day, which is why it works so well as a wind-down. Every note also begins with a hammer hitting a string, and those sudden starts are exactly what keeps a light sleeper coming back up, so Tock fades it out rather than running it to your alarm.Play a clip here
- Binaural beatsRecordedA binaural beat is something your brain constructs when each ear receives a slightly different tone, so it exists only over headphones and vanishes the moment you use a speaker. The sleep evidence is limited, mixed and mostly short-term, and Tock does not include a binaural beats track, partly because sleeping in headphones brings problems of its own.
Questions people ask
Do sleep sounds actually work?
For masking, yes, and that is the part with the least argument behind it. A steady broadband sound raises the floor so a door closing or a car passing no longer stands out enough to wake you. The claims about sounds directly improving sleep depth are much thinner, and worth treating with some suspicion.
Which is better for sleep, white noise or brown noise?
Most people find brown noise easier to listen to for hours because its energy sits lower, so it reads as a distant waterfall rather than a hiss. White noise is better at covering speech. Try both for a week each rather than trusting either recommendation.
Is it safe to play sound all night?
Keep it quiet enough that you could hold a conversation over it. Sound played close to the ears for eight hours a night at high volume is a genuine risk, which is why Tock has a distance control on 42 of its sounds and why the sensible setting is Far.
Can I mix sounds together in Tock?
Yes, up to four at once, and you can save the combination as a mix. Most of the 63 sounds are generated on device sample by sample rather than looped from a file, so a layered bed never falls into an audible repeat.
Elsewhere on the site
Different corner of the same problem.
- FeaturesSleep scoreThe sleep score is a single number for a night, sitting at the top of that night detail view. Underneath it are the parts that produced it, and across nights the insights cover 21 metrics in 7 groups plus long-run measures like sleep regularity and sleep debt.
- Tock for youNew parentsYou do not wake up to an alarm any more, you wake up to a small person, three or four times, and then you have to be a functioning adult by seven. The night is not so much short as it is in pieces.
- AlternativesTock vs RiseChoose Rise if planning your day around energy peaks and a running sleep debt is what actually changes your behaviour. Choose Tock if you want the alarm itself to be smarter, the night recorded from the phone, and a coach that can talk about what it heard.
- RoundupsThe best sleep apps for iPhone, sorted by what you're fixingFor iPhone, the best sleep app depends on the problem. Tock is the best all-round pick when the alarm and the morning are what is broken, Apple Health Sleep is the free place to start, Calm is for people who cannot fall asleep, AutoSleep is for Apple Watch owners, Rise is for sleep debt and SnoreLab is for snoring.
- Wake timesWaking up at 6:30amBedtimes by sleep cycle for a 6:30am alarm.
- Wake tonesGentle alarm soundsA gentle alarm works when it catches you at a light moment and fails when it lands in the heaviest part of your night, which is a timing problem rather than a volume one. Tock watches movement and sound across the 30 minutes before your alarm and rings early at a lighter moment if it finds one, with your set time as the fallback.
Sixty three sounds, none of which loop
Most of them are generated on device, sample by sample, so no two nights sound the same. Layer four, save the mix, and let the alarm find a lighter moment in the morning.