SchlummerSchlummer guide
Offline Sleep Sounds for iPhone
Most sound apps ship you a pack of audio files, or stream them. Schlummer generates the sound on your phone while you listen, which is why it works on a plane, in a basement and on a hotel Wi-Fi that never connects.
Generated, not downloaded
Behind every one of the twelve entries is a small synthesizer rather than a recording. Schlummer produces a stream of noise in real time, either white, pink or brown, then shapes it: a low pass filter takes the harshness off, and a very slow modulation swells the volume up and down so the result breathes instead of hissing flatly.
Ocean is brown noise with a slow, deep swell. Rain is filtered pink noise with no swell at all. Storm is the same family with a heavier filter and a stronger, faster surge. Fan is a steady, tightly filtered hum. It is the same three ingredients arranged twelve ways.
The practical consequences are the interesting part:
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No download step
Nothing to fetch before the first use. Install the app on the plane and the sounds work immediately.
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No data used
Nothing streams while you sleep, so a night of sound costs zero megabytes of your plan.
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No storage taken
There are no audio files to store, so the sound library adds nothing to the space the app occupies.
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No loop point
The audio is produced continuously, so there is no seam where a short sample restarts and pulls you back awake.
The twelve, and which four are free
Four soundscapes are in the free version. The other eight are unlocked by Schlummer Pro.
| Soundscape | Character | In the free version |
|---|---|---|
| White Noise | Flat, bright, unshaped | Yes |
| Soft Noise | Pink noise, gently softened | Yes |
| Rain | Steady filtered patter, no swell | Yes |
| Ocean | Deep, slow surge | Yes |
| Wind | Broad, moving, mid weight | Pro |
| Stream | Light, high, continuous | Pro |
| Storm | Heavy and strongly swelling | Pro |
| Fan | Constant machine hum | Pro |
| Summer Night | Thin and quick, a shimmer | Pro |
| Depth | Very dark, very slow | Pro |
| Cabin | Muffled, room like | Pro |
| Void | The darkest and quietest of the set | Pro |
The sleep timer
Off, 15, 30, 45 or 60 minutes. Most people do not want a fan running until morning, and a timer means you do not have to wake up to turn one off. Set it before you start the sound, not after.
Twelve sounds that need no connection and take no space.
Four are free. Schlummer Pro unlocks the rest and removes the ads.
When a sample based app is the better buy
Synthesis is honest about what it is. If what helps you sleep is a real recording of a thunderstorm rolling over a valley, a crackling fireplace, a train, birdsong or a human voice reading a story, Schlummer will not give you that and no amount of filtering will fake it. Those apps exist, they are good at it, and the files they download are the reason they work.
Schlummer's set is textures: noise, water, wind, machines. If that is what you reach for, the fact that it needs nothing from the network is a real advantage. If you want a soundscape with events in it, buy the other kind of app.
Where to go next
- The alarm at the other end, which also generates its sound rather than shipping one.
- What the app is doing while you sleep, and what it can honestly tell you in the morning.
- Everything Schlummer does on the home page.