A white noise app that actually plays all night

It's a familiar sequence. You finally drift off to a rain video or a free noise app. Sometime after midnight the sound cuts out — an ad starts shouting, the video ends, the Wi-Fi hiccups, or the phone quietly kills the app to save battery. Now you're awake in a silent room, more alert than when you started, trying to get it playing again with a screen shining in your face.

The honest answer first: this isn't your phone being broken, and it isn't you doing something wrong. Most of the things people use for sleep sound were never designed to run unattended for eight hours. Once you know the four reasons playback stops, it's easy to check whether any app — ours included — will make it to morning.

Why does my white noise app stop playing at night?

Nearly every middle-of-the-night cutout comes down to one of these:

• It's streaming, and the connection blinked. YouTube videos and streaming apps pull sound over the internet all night. A router reboot, a weak signal in the bedroom, or a brief outage at 1am and the sound stops — sometimes with a loud error chime.
• Ads interrupt it. Free video platforms insert ads. An advertisement at full brightness and full volume is close to the worst thing that can happen to someone in light sleep.
• The app isn't built for background audio. iOS only lets audio keep playing with the screen locked if the developer specifically builds for it. Apps that skip that step go silent the moment the phone locks — which is why some people resort to leaving the screen on all night, lighting up the room and draining the battery.
• The video simply ends. A "10-hour rain" video has an ending, an autoplay suggestion, and no promise about what plays next. A short loop with an audible seam is nearly as bad: that tiny skip every few minutes is exactly the kind of change your brain listens for.

Steady sound helps precisely because it's steady. Research on broadband noise for people with difficulty sleeping found it shortened the time to fall asleep in a noisy environment¹ — but the operative word is continuous. Sound that stops mid-night can wake you exactly the way a door slam would.

Can a sleep sounds app work with the screen locked?

Yes — if it's built as a proper audio app. Lull registers with iOS as background audio, the same way a music or podcast app does. That means:

• You press play, lock the phone, put it face-down, and the sound continues — no screen glow, no "keep the app open" tricks.
• Play, pause, and volume live on the lock screen all night. If you wake at 3am and want it a touch quieter, that's one swipe and one tap, without unlocking anything.
• iOS treats actively playing audio as something the user wants, so the system doesn't shut it down to save power the way it does with idle apps.

If you've been propping your phone screen-up on the nightstand to keep a video alive, this is the single biggest upgrade: the room goes fully dark and the sound keeps going.

Does it work offline — even in airplane mode?

This is where streaming and downloading part ways. Lull's sounds play from files stored on your iPhone, not from a server. Once a sound is on your device, the internet is out of the picture entirely:

• Airplane mode works. Some people prefer flipping it on overnight anyway — no calls, no notifications, no radios. Lull plays through it, all night.
• Wi-Fi dropouts don't matter. The router can reboot at 2am and you'll never know.
• It travels. Hotel rooms with terrible Wi-Fi, the guest room at your kids' place, an actual airplane — the sound is already on the phone.

And because the sounds are engineered as seamless loops rather than long recordings, there's no ending to hit at 4am and no audible seam to catch your ear. The last hour sounds exactly like the first.

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Does playing white noise all night drain the iPhone battery?

Less than you'd expect — audio playback with the screen off is one of the lightest things a phone does. The screen is the big battery consumer, which is exactly why the "leave a video playing face-up" workaround hurts twice: it lights the room and empties the battery. With the screen locked and audio playing locally (no streaming radio keeping the connection alive), a typical iPhone gets through a full night with plenty to spare.

The simplest habit, and the one most people land on anyway: plug the phone in on the nightstand. Then battery never enters the equation, and the alarm is guaranteed for morning too.

What "all night" looks like in Lull

Lull was built around one promise: press play at 10pm, and the sound is still there — or has ended gently, on your schedule — at 6am. Concretely:

• 43 sounds, stored on your phone. Classic White Noise, Pink Noise, Brown Noise, and Green Noise for pure broadband beds; Box Fan, Ceiling Fan, and Air Conditioner if you want the familiar mechanical version; Steady Rain and Ocean Waves if you'd rather the natural one. If you're not sure which noise color suits you, our guide to brown noise vs white noise walks through it honestly.
• Mix up to three sounds with independent volumes — say, Brown Noise under Rain on the Window — and save it as a one-tap mix so tomorrow night takes two seconds, not two minutes of fiddling in the dark.
• All night, or a timer with a gentle fade. Leave it running until morning, or set a timer that eases the volume down over the final minutes instead of cutting to silence. There's a real tradeoff between the two — our guide to sleep timers and fade-out lays it out.
• Lock-screen controls all night, so a 3am adjustment never means unlocking the phone into a bright screen. If 3am waking is the actual problem you're solving, we wrote about waking at 3am and getting back to sleep too.

A fair way to judge any sleep sound app

Whatever you end up using — Lull or anything else — it should pass these four checks before you trust a night's sleep to it:

• Does it keep playing with the screen locked, without tricks?
• Does it play with Wi-Fi off or in airplane mode?
• Are the loops seamless, with no ending and no audible seam?
• Can it end gently on a timer instead of stopping abruptly?

One honest caveat: an app can fix interrupted sound, not interrupted sleep from every cause. If you're waking repeatedly gasping, snoring heavily, or exhausted despite full nights, that's worth raising with your doctor — steady sound is comfort and masking, not treatment.