All 33 sounds
Recordings come from licensed sound libraries, cut and levelled for sleep, and played so they never loop audibly. Noise colors and tones are generated on your phone. 8 are free; Premium unlocks the rest.
Noise colors
Generated on your phone, steady from the first second to the last. 7 sounds
White NoiseEqual energy across the whole range. Bright and even, the classic choice for covering voices and street noise. 
Pink NoiseSofter than white: the high end is turned down, so it sounds more like steady rain than static. 
Brown NoiseMost of the energy sits low. A deep, rounded rumble with almost no hiss. 
Deep BrownBrown noise with everything above about 200 Hz filtered away. Felt as much as heard. 
Green NoiseNoise centred on the middle of the range, around 1 kHz. Fuller than white, lighter than brown. 
Blue NoiseOnly the highs, above about 4 kHz. Airy and crisp, best at a low volume or in a mix. 
Violet NoiseThe very top of the range, above 6 kHz. A thin, fine hiss. Few people use it alone; it can add air to a mix at low volume.
Nature
Field recordings from licensed sound libraries. 12 sounds
RainA real recording of gentle, steady spring rain. Turn the tone down for rain heard from indoors. 
Ocean WavesWaves on the Baltic coast, a steady wash of surf. No seagulls, no voices. 
CricketsA summer night outdoors. Crickets close by and a wide, quiet yard behind them. 
ThunderRecorded rain with thunder at random moments. Every strike fades in, never cracks; set how often and how far away. 
RiverA spring stream flowing over stones, recorded close up. Constant, bubbling water. 
Forest BirdsA countryside dawn chorus. Better for waking slowly or reading than for the middle of the night. 
WindWind moving through a forest, a soft rushing that swells and settles. 
FrogsA chorus of frogs at night in rural Brazil, with crickets close by. 
Rain on TentRain drumming on a tent, recorded from inside. Close, soft and steady. 
Rain on RoofRain on the roof, heard from the attic underneath. Even and close, with no thunder. 
Rain on CarRain on the roof and windows of a parked car, heard from inside. A soft, dense patter. 
CicadasCrickets and cicadas on a warm summer day. A bright, shimmering texture.
Home & travel
The machines and places people fall asleep to. 9 sounds
FanFans running in a quiet room. The sound many people already sleep with, without the draft. 
FireplaceA wood fire burning in a fireplace, crackling and settling. 
DryerA tumble dryer turning. Warm, even drone. 
AirplaneA cabin hum generated on your phone, shaped to match a Boeing 757 at cruise. The sound that sends half the plane to sleep. 
TrainInside a quiet intercity train at speed. A deep, steady rumble, no announcements. 
Night DriveInside a car on an empty highway at night. Road hum and a low engine, no radio, no indicator. 
Cat PurringA cat purring up close, slow and deep. 
ShowerA running shower. Warm, even water noise. 
Air ConditionerAn air conditioner vent humming. A low, steady drone.
Calm & rhythm
Slow, simple sounds for winding down. 5 sounds
HeartbeatA slow, steady heartbeat. Set the pace anywhere from 40 to 100 beats per minute. 
LullabyBrahms' lullaby on a music box, recorded live. 
ShushSoft shushing that swells and settles. Choose a slow or quicker rhythm. 
432 HzA pure, steady 432 Hz tone. Some people like a single tone under other sounds. We make no health claims for it. 
528 HzA pure, steady 528 Hz tone, slightly brighter than 432 Hz. No health claims, just a tone.
Where the recordings come from
The nature and home recordings come from Freesound, under CC0 or CC BY licences; the CC BY authors are credited below, on each sound's page and in the app under Settings, Sound Credits. We cut a long, clean stretch from each, level them to a similar loudness so nothing jumps out when you switch, and let the app pick random segments as it plays. Thunder strikes are separate recordings mixed over rain, each with a slow fade-in.
Sound credits
- Fireplace: “1 Hour of Relaxing fireplace with Crackling Sounds” by Hear_it_use_it (Freesound), CC BY 4.0, edited (excerpt, filtered and levelled).
- Wind: “strong wind in the forest” by inchadney (Freesound), CC BY 4.0, edited (excerpt, filtered and levelled).
- Rain on Roof: “Rain in the Attic” by naturenutt (Freesound), CC BY 4.0, edited (excerpt, filtered and levelled).