Susurella: Sleep Sound Mixer

Pick the sounds you want, layer them, and fall asleep to a mix that is yours.

Susurella is an offline sound mixer for sleep. Tap a sound and it starts. Tap another and the two play together. Every layer keeps its own volume slider, so you can put rain up front and hold the ocean underneath it.

WHAT IS INSIDE
- 26 CC0 nature loops: ocean, beach, stream, mountain stream, waterfall, rain, summer rain, rain on a roof, forest, forest stream, forest wind, morning birds, wind in trees, campfire, fireplace, fountain, night crickets, singing bowl, storm, frogs, purring, cave, boat cabin, fan, air conditioner and ventilation.
- 4 noise colours generated on the device: white noise, pink noise, green noise and brown noise.
- 6 complete classical piano performances, played through rather than looped.
- Nothing is locked. There is no sound pack to buy.

YOUR OWN AUDIO
Add files from your device. mp3, ogg, wav and flac play directly; aac and m4a are converted on the device. They become mixer layers like any other sound, and they never leave your phone.

SLEEP TIMER
Choose a length from 5 to 120 minutes and the mix fades out and stops. Or switch to the adaptive timer: the phone watches for the moment you stop moving and fades early, treating your chosen length as a ceiling instead of a fixed end. Nothing about that is recorded or analysed.

NIGHT MODE
Once a session starts the screen goes dark and shows the countdown and a stop button. That is all it shows.

OFFLINE, NO ACCOUNT
Every sound ships inside the app. No sign-up, no cloud, no sync, and no data spent while you sleep. Airplane mode works.

HOW ADS WORK HERE
We would rather tell you exactly than claim "no ads" and be wrong.
- No subscription. Not now, not later.
- A banner sits at the bottom of the setup screens.
- During a sleep session there are zero ads. The banner comes down and nothing full-screen can appear.
- No ad ever interrupts what you are playing.
- There is a launch ad when you reopen the app.
- One purchase removes every ad, permanently. Restore is always available.

Available in English, Korean, Japanese, German, French, Spanish, Italian, Portuguese and Chinese (Simplified and Traditional).

Sounds are CC0 (public domain), sourced from BigSoundBank. The licence notice is in Settings.