Nightwool

Why your sleep sound app stops in the middle of the night (and how to fix it)

The usual reasons white noise and rain sounds go silent at 2 a.m. on iPhone and Android: battery limits, Screen Time, overnight updates, headphones, and the app itself.

By Michal Piják11 min read

How this guide was made

Written by Michal Piják, founder of Nightwool. The 23 sources are listed at the end as plain links, and claims about research are checked against the original paper or its abstract wherever we can get it.

Illustrations are AI-assisted.

We make Nightwool, a sleep-sounds app, so we have an interest in this topic. The app is mentioned only where it's relevant, and there are no sponsored or affiliate links.

Our editorial standardsCorrections and updates

Illustration: a dark bedroom in the small hours, a phone lying face down on a wooden nightstand with a charging cable plugged in, a small round speaker with one dim amber light, a glass of water and the edge of a bed in moonlight
Illustration: Nightwool (AI-assisted)
On this page
  1. How often it happens
  2. First, work out when it stops
  3. Android fixes
  4. iPhone fixes
  5. Fixes that work on any phone
  6. When it’s the app, not your phone
  7. How Nightwool handles this
  8. Questions
  9. Sources

A sleep sound app usually stops at night for one of four reasons. The phone limits the app in the background to save battery, something interrupts the sound (a call, an alarm, earbuds running out of charge), the phone restarts or updates itself, or the app has a bug. On Android the first one is the most common thing to check. On iPhone it is more often Screen Time, a timer or an overnight update.

The sudden silence is what wakes you. A sleeping brain reacts to change more than to steady sound, which we explain in why some people need noise to sleep. So a sound that stops at 2 a.m. can be worse than no sound at all. Below: how to tell which cause you have, then the fixes for Android, iPhone and both.

How often it happens

When we read 5,014 reviews of 28 sleep sound apps, 167 of the 1,794 one- and two-star reviews said the sound stops at night, in the background or after a while. 160 of those were from Google Play.

negative reviews say the sound stops at night
167
of them are from Google Play
160
mention waking up
53
say it began after an app update
~10
167 one- and two-star reviews that say the sound stops at night or in the background, out of 1,794 negative reviews of 28 apps.

The reviews show two things. First, people lose sleep over it:

“I’m going to change apps because I’m tired of waking up at 2am to turn the sound back on.”

White Noise Lite review

Second, phone settings are not always the answer. Several reviewers had already changed their battery settings, and the sound still stopped. About 10 of the 167 say it began after the app updated, 2 after an Android update, and one that the app “turns off when updating in the middle of the night.” We come back to that below.

First, work out when it stops

The moment it stops is the best clue. Check the morning after:

When it stops Likely cause Where to look
A few minutes after the screen goes off, most nights The phone restricts the app in the background (mostly Android), or a bug Battery settings for the app
At the same time every night Screen Time or a bedtime schedule, a sleep timer, a scheduled restart Screen Time, Digital Wellbeing, the app’s timer, the Clock app
After a call, an alarm or a voice assistant An audio interruption the app didn’t recover from The app (it should resume by itself)
When your earbuds or a Bluetooth speaker disconnect Sound pausing on purpose so it doesn’t jump to the phone speaker Charge, or use the phone or a wired speaker
The phone asks for your passcode in the morning, not Face ID or fingerprint The phone restarted overnight, usually for an update Automatic update and restart settings
Only when you’re away from home Wi-Fi, or randomly with streamed sounds The app streams sound and lost the connection Download sounds or use an offline app

If the app is missing from your recent apps list in the morning, the system closed it or it crashed. If it’s still open but silent, something paused it.

Android fixes

Android limits what apps can do in the background to save battery, and phone makers add their own limits on top. A sleep app that plays correctly runs a so-called foreground service, which is why you see a notification with play controls while it plays. Google lists media playback as a foreground service type, for audio that continues while the app isn’t on screen.

Set the app’s battery use to Unrestricted

This is the fix most people need. If an app’s battery mode is set to Restricted, Android’s documentation says its existing foreground services are removed from the foreground, which can end the sound.

  • Pixel and most phones: Settings > Apps > See all apps > (the app) > App battery usage. Turn on Allow background usage and choose Unrestricted (older versions show the three choices Unrestricted, Optimized and Restricted directly).
  • Samsung: Settings > Apps > (the app) > Battery > Unrestricted.

Take it off Samsung’s sleeping apps lists

Samsung phones can put apps to sleep on their own. Go to the battery settings (Battery and device care or Device care, depending on your One UI version) > Background usage limits.

  • Make sure the app is not under Sleeping apps or Deep sleeping apps. Samsung says deep sleeping apps “will never run in the background.”
  • Add it to Never sleeping apps.
  • If you use the app only at night, consider turning off Put unused apps to sleep, or the app may end up on the list again.

Xiaomi, OnePlus, Huawei and other brands

The site dontkillmyapp.com ranks phone makers by how aggressively they stop background apps. Huawei, Xiaomi, OnePlus and Samsung share the worst score. For Xiaomi phones (MIUI, now HyperOS), it suggests three steps:

  1. Turn on Autostart for the app (Settings > Apps > the app > App permissions).
  2. Set the app’s battery saver to No restrictions.
  3. Lock the app in the recent apps screen (long-press its card and tap the lock).

For other brands, look up your phone on dontkillmyapp.com. Paths change between versions, so the exact names may differ on your phone.

Check that you see a playback notification

While a sleep sound plays, you should see a notification with play and pause buttons. If there is none, the app may not be using a foreground service. That matters more than before: on Android 17, Google says audio from an app that has no visible screen and no proper foreground service fails silently, with no error. That applies to all apps on Android 17, old or new. It’s something only the developer can fix.

Check Digital Wellbeing and app timers

Bedtime mode silences notifications and can dim or gray out the screen. Google’s help doesn’t say it stops apps. App timers are different: “When you run out of time, the app closes.” If you set a daily timer on the sleep app, or on a group of apps, remove it.

Overnight restarts and updates

Many Android phones restart to finish a system update. Samsung phones can also restart on their own under Device care > Auto optimization > Auto restart, when the screen is off and the battery is at least 30%. Samsung notes that in some countries, emergency security updates may restart the phone even with automatic downloads turned off.

An app that updates itself while it plays also stops. To rule that out, turn off automatic updates for the sleep app only: open its page in the Play Store, tap the three dots and untick Enable auto update. Update it by hand during the day.

iPhone fixes

On iPhone, apps that play audio in the background are allowed to keep going when you lock the phone, as long as the app declares background audio. Sleep apps do. In our review data, overnight stops came up in 3.8% of negative App Store reviews against 10% on Google Play, though the two samples were collected differently. When it does happen, the usual causes are below.

Low Power Mode and Background App Refresh are usually not the cause

These two settings are the most common advice and usually the wrong one.

  • Low Power Mode: Apple’s list of what it limits includes Background App Refresh, automatic downloads, mail fetch, brightness and visual effects. Audio playback is not on it.
  • Background App Refresh: this lets suspended apps check for new content. Playing sound is a separate background mode, so turning refresh on or off doesn’t change it.

Screen Time and Downtime

Downtime and other Screen Time schedules limit which apps you can use at night. With Block at Downtime turned on, apps that aren’t allowed are blocked. Apple doesn’t say whether sound that’s already playing stops, and people report both.

To rule it out, go to Settings > Screen Time > Always Allowed and add the sleep app. Apple says apps on that list can be used at all times, whatever your schedule. Also check that the app isn’t in an App Limit or time allowance.

The Clock app’s timer

The iPhone timer can stop any sound when it ends. In the Clock app, open Timer > When Timer Ends. If Stop Playing is selected, every app goes quiet when the timer runs out. It’s useful on purpose, and confusing if you’ve forgotten it’s set. Use the sleep app’s own timer instead, ideally one that fades out.

Automatic iOS updates

With automatic installs on, Apple says your iPhone “downloads and installs it overnight while charging and connected to Wi‑Fi.” The update restarts the phone, so the sound stops. A passcode prompt in the morning (instead of Face ID) is the giveaway.

Go to Settings > General > Software Update > Automatic Updates and turn off automatic installing of iOS updates. You can leave automatic downloads on and install the update yourself during the day.

Headphones, AirPods and Bluetooth speakers

Apple’s guidelines tell apps to pause when headphones disconnect, so a sound meant for your ears doesn’t suddenly play from the phone speaker. If your AirPods or sleep earbuds run flat at 3 a.m., the silence is by design. Charge them fully, use one earbud at a time if they allow it, or play from the phone or a speaker. The same goes for a Bluetooth speaker that turns itself off when idle or out of power.

Calls, alarms and the app being closed

A call, an alarm or Siri pauses other audio. When it’s over, the app is supposed to resume by itself; if it doesn’t, that’s the app. iOS also closes background apps when it runs short of memory, and an app that uses a lot of memory over a long night is more likely to be closed. That one is for the developer to fix, so report it.

Fixes that work on any phone

  • Use sounds stored on the phone. Streamed sounds stop when Wi‑Fi drops or the phone limits network use at night. Downloaded or built-in sounds don’t need a connection.
  • Charge the phone, and keep it cool. A dying battery switches on power saving, and a hot phone under a pillow can slow down or stop charging.
  • Check the app’s own timer. A timer you set weeks ago, or a default timer, is an easy one to miss.
  • Update the app, and read the recent reviews. If many people report stops after the latest version, it’s not you.
  • Test one full night with your phone’s speaker. If it plays all night on the speaker, the problem is Bluetooth or headphones.

Avoid the tip of keeping the screen on all night. It is bright, wastes battery and can overheat a phone on a charger. For volume and timer advice, see is white noise safe to sleep with every night.

When it’s the app, not your phone

Settings can’t fix a bug. These are signs the problem is the app:

  • It started right after an app update and your settings haven’t changed.
  • It stops even with battery set to Unrestricted and the app off every sleeping list.
  • Other audio, like a podcast app, plays all night on the same phone.

One reviewer put it plainly:

“An app shouldn’t need unrestricted access to the battery to work properly.”

myNoise review

That is fair. A well-built sleep app on Android starts its foreground service when you press play and keeps it running until you stop the sound, so the battery setting is a safety net rather than a requirement. If the app stops anyway, write to the developer with your phone model, the system version, roughly when it stopped and what you were playing. That’s what lets them reproduce it.

How Nightwool handles this

We built Nightwool with these failures in mind, and we’re still testing it across more phones. On Android, it plays as a media service with a notification and keeps playing after you swipe the app away. After a call or alarm, it is built to resume when the system says it may. When headphones or a Bluetooth speaker disconnect, it pauses instead of jumping to the phone speaker. All sounds are stored on the phone, so nothing depends on Wi‑Fi.

If it ever stops for you in the night, tell us at support@nightwool.com with your phone model and the time. You can also browse all the sounds in your browser first.

Questions

Why does my white noise app turn off when my iPhone locks?

An app needs Apple's background audio mode to keep playing on a locked iPhone. Apps built for sleep have it, so if one stops right at lock, check that it isn't a web player in Safari and that the app is up to date. If it stops later in the night, look at Screen Time, the Clock timer's Stop Playing option, automatic iOS updates and your headphones.

Does Low Power Mode stop sleep sounds?

Apple's list of what Low Power Mode limits includes Background App Refresh, automatic downloads, mail fetch, brightness and some visual effects. Audio playback is not on it. An app that keeps playing on a locked phone normally keeps playing in Low Power Mode too.

Why does YouTube stop when I lock my phone?

Background play on YouTube is a Premium feature. Without Premium, the YouTube app stops playback when you leave it or lock the screen. A sleep sound app or a downloaded file doesn't have that limit.

Should I leave the screen on so the sound keeps playing?

It's a common tip, but a lit screen all night is bright, uses battery and can overheat a charging phone. Fix the background settings instead. If you must, turn the brightness all the way down and lay the phone face down.

Does iPhone's built-in Background Sounds keep playing when the phone is locked?

Only if you allow it. Under Settings > Accessibility > Audio & Visual > Background Sounds there is a Stop Sounds When Locked switch. Turn it off to keep the sound playing on a locked phone.

Sources

Michal Piják, Founder of Nightwool

Michal is an independent developer in Bratislava, Slovakia, and builds Nightwool on his own. He writes these guides from published research and official health guidance, and links every source so you can check it.

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