Slo: Sleep Sounds, Brown Noise

Melted Butter

Contains adsIn-app purchases

About this app

Sleep sounds app and sound machine with brown noise, white noise, green noise, rain and fan sounds to help you sleep better, focus, and relax. Download the best sleep sounds and noise machine app today.

Premium Sleep Sounds

Experience scientifically proven audio for better sleep. Slo offers brown noise for deep focus, white noise to block distractions, pink noise and green noise for restful sleep, and nature sounds like rain and ocean waves.

Key Features

• Brown noise - Deep, rich tones for concentration and sleep
• White noise - Mask background noise and distractions
• Pink noise & green noise - Gentle frequencies for deeper sleep
• Rain sounds - Natural rainfall and thunderstorms
• Fan sounds - Ceiling fan, table fan, and airplane cabin noise
• Nature sounds - Ocean waves, waterfalls, forest, river, and birds
• Cozy ambience - Fireplace, campfire, train, and wind sounds
• Binaural beats - Calming frequencies for meditation and focus
• Baby sleep - Lullabies and heartbeat sounds for little ones
• Sleep timer - Stops playback after you fall asleep
• Mix multiple sounds with individual volume control
• Offline playback - downloaded sounds work without internet

Benefits

Sleep Better: Fall asleep faster with soothing sleep sounds designed for bedtime. Improve sleep quality naturally.

Boost Focus: Block distractions with deep, steady noise for studying, working, or reading. Great for ADHD focus and deep work.

Reduce Stress: Calm your mind with relaxing nature sounds. Lower anxiety and promote relaxation.

Aid Meditation: Enhance mindfulness with ambient sounds and binaural beats that help you stay present.

Why Choose Slo?

The #1 sleep sounds app trusted by millions. High-quality audio, a simple interface, and a full sound machine experience. Free to download with premium sounds available.

Download Slo now and experience better sleep tonight.


FREQUENTLY ASKED QUESTIONS

What is the best app for brown noise?
Slo plays continuous, high-quality brown noise tuned for deep sleep and focus, with smooth, gapless playback all night long.

Does brown noise actually help you sleep?
Yes. Studies show deeper noise colors reduce the time to fall asleep and mask disruptive sounds like traffic, snoring, and noisy neighbors - especially effective for light sleepers.

What's the difference between brown noise, white noise, pink noise, and green noise?
White noise contains all frequencies equally (like static). Pink noise emphasizes lower frequencies (like steady rain). Green noise centers on the soothing mid frequencies of nature. Brown noise goes deepest - like a rumbling waterfall or strong wind. Slo offers all of them so you can find what works best for you.

Is this a good white noise machine for babies?
Yes. Slo works great as a baby sound machine - many parents use white noise, lullabies, or heartbeat sounds to help their baby fall asleep faster and stay asleep longer.

Can I use it for studying and focus?
Absolutely. Many users prefer brown noise or fan noise for deep work, studying, and ADHD focus. Continuous playback helps maintain concentration for hours.

Does it work offline?
Yes. Downloaded sounds play without an internet connection - perfect for flights, camping, or areas with no signal.

Is Slo free?
Slo offers free sounds with a timer. Premium unlocks the full sound library, mixing, and unlimited playback.

Can I mix multiple sounds together?
Yes. Slo lets you layer sounds - combine brown noise with rain, add thunder to a fan sound, or create your own custom soundscape with adjustable volumes.

Does Slo have a sleep timer?
Yes. Set the sleep timer to stop playback automatically - 15, 30, 60 minutes, or a custom duration.

Ratings and reviews

Edit: Im changing my review to 4 stars instead of 1 only bc I did finally get help. Yes the app, showed the card it would charge after the free trial, and yes, I did use the app free one time during the trial period. It was difficult to get help, as the first person told me there was nothing that could be done, but someone followed up and helped Delete my subscription!! I only wanted the 3 day free trial and the app is not allowing me to cancel. Now.youre charging me for something I dont want!!

absolutely love this app! i depend on white noise as background noise due to sound sensitivities and this app runs it perfectly! i love that running the sound in the background is a free option, where as most apps make you pay for that, or it doesnt work. i switched to this one for that reason and i dont plan on going back! also not to mention the variety of sounds that are free and even more if you pay the subscription. keep doing what you're doing the way you're doing it!

This app is great except for the fact that it shuts off randomly during the night and wakes you up. If it were consistent and played throughout the night it would be 5 stars easily. I've done all the optimization they recommend and it still shuts off every night. Reply: Yes my phone is always on the charger every night when using the app. Edit: What I'm hearing from the developer is that the app isn't compatible we with Samsung and instead of fixing the issue they blame the phone manufacturer.

What’s new

Bug fixes and improvements