White Noise Deep Sleep Sounds vs Slo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
White Noise Deep Sleep Sounds
This app provides a variety of calming sounds to help adults and children fall asleep faster. It also aids in focus and meditation by blocking distractions and creating a relaxing atmosphere. Enjoy a wide selection of free and premium ambient audio for better rest and concentration.
- Calming nature sounds
- Sleep association cues
- Focus and meditation aid
- Mixable soundscapes
- Sleep timer
- Background playback
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** Relaxing Scenes and Sounds ** — Apple ** Best White Noise Machines for Sleep ** — ABC News ** The Ultimate Guide to Sleep Sounds ** — Health.com Say goodbye to sleepless nights and fussy babies. White Noise and Deep Sleep Sounds will lull you or your child to sleep with calming and relaxing sounds. Download the app today and sleep like a baby tonight! White Noise and Deep Sleep Sounds helps ADULTS sleep better: - Blocking out unwanted noises - Forming sleep associations that cues you to fall asleep - Helping you feel calm, relaxed, and soothed at night White Noise and Deep Sleep Sounds helps BABIES and INFANTS get better sleep: - “Whooshy” noises that simulate the environment of the womb - Sleep association that cues your baby to fall asleep - Engaging your baby’s calming reflex allows baby to sleep longer - Blocking outside noises that wake your baby - Creating a familiar routine that will help baby feel safe White Noise and Deep Sleep Sounds help you STUDY, FOCUS, or MEDITATE: - Improve focus and creativity by preventing outside distractions - Creating a pleasant and zen like environment for meditation - Canceling the noise around you - Adding natural ambient background audio Better than an actual sound machine or radio. Our sounds are professionally recorded to add the perfect background noise or ambience to your office, bedroom or nursery. Great for travel in noisy hotels, don't bother lugging around an actual sound machine when all you need is an iPhone or iPad. Include sounds in categories ranging from sleep, meditation, ASMR, lullaby, solfeggio healing frequencies, and classical and relaxing music. Free sounds: Air Filter Fan Shush (Shhh) Baby Shusher Vacuum Cleaner Airplane Cabin Driving in the Rain Heartbeat Cat Purring Crickets Lite Rain Medium Rain Rain on Tent Distant Thunder Rolling Thunderstorm Ocean Waves Brown Noise Pink Noise White Noise Classical Piece: Gymnopedie Number 1 30+ free sounds Enjoy soundscapes, binaural beats, and binaural recordings, which create an enhanced 3D stereo sound. Some premium sounds include: Green Noise Blue Noise Box Fan Forest at Dusk Forest Creek Ocean Windstorm Ocean Waves Crashing on Rocks Rain on Umbrella Light Backyard Rain Heavy Backyard Rain Forest Birds Forest Crickets Lapping Lake Waves Heavy Ocean Waves Thunder Close Rain & Water Sounds Deep Healing 528 Hz Binaural Music 4 Hz, 40 Hz, and 432 Hz Binaural Music Tibetan Singing Bowls for Meditation Lullabies Classical Music Relaxing Music ASMR 250+ more Features: Sleep Timer Mix multiple sounds to create a soundscape Play on launch Today Widget Plays in the background Dark color theme AirPlay 2 If you're a night owl or have insomnia, this app will help you maintain your circadian rhythm for a better mood. Use regularly over several weeks to obtain the best results and improve your sleep cycle. Keep a consistent bedtime at night and rise every morning at the same time. You'll feel well-rested and balanced. Compatible with most smart speakers and all Bluetooth LE speakers, headsets, and buds such as Bose or Sonos. The free version will play sounds for eight hours. Subscription is required for continuous play. Terms and pricing: An optional auto-renewing yearly subscription at $49.99 USD/year to provide unlimited access to the sleep sounds library and premium features while you maintain an active subscription. Payment will be charged to the payment method connected to your iTunes Account when you confirm the subscription purchase. Subscriptions automatically renew unless auto-renew is turned off at least 24-hours before the end of the current subscription period. You will be charged for renewal within 24-hours prior to the end of the current period. You may manage your subscription and auto-renewal may be turned off by going to your Account Settings. Terms of service: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy policy: https://kitefaster.com/privacy-policy/
Slo
This app offers a variety of scientifically proven sleep sounds, including brown, white, and pink noise, as well as nature sounds like rain and ocean waves. It helps users fall asleep faster, improve focus, reduce stress, and aid meditation with its high-quality audio and customizable features.
- Brown, white, and pink noise options
- Nature sounds (rain, ocean waves)
- Timer functionality
- Mix multiple sounds
- Offline playback
- Improve sleep quality
- Boost focus and concentration
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Slo is a brown noise and sleep sounds app for iPhone, iPad, and Mac, with 150+ curated sounds for sleep, focus, and relaxation. Play deep brown noise on its own, or mix it with rain, waves, and fan sounds — each layer with its own volume — and set a sleep timer that stops playback automatically. KEY FEATURES • Brown noise – deep, low-frequency rumble many people choose for focus and sleep • White, pink & green noise – broadband noise colors for masking background sound • Binaural beats & frequencies – binaural beats, solfeggio tones (396–963 Hz, including 432 Hz and 528 Hz) and Schumann resonance tones • Rain sounds – steady rainfall and distant thunderstorms • Waves & water – ocean waves, river, waterfall • Fan sounds – ceiling fan, table fan, airplane cabin • Nature & ambience – forest, birds, wind, fireplace, campfire, train • Sound mixing – layer sounds, each with its own volume control • Sleep timer – playback stops on its own after you drift off MADE FOR • Light sleepers who use steady sound to mask traffic, neighbors, or a snoring partner • Students and deep workers who keep brown noise or fan noise running for hours • People who wind down to binaural beats, solfeggio tones, or steady frequencies • People who use sound masking at night to make tinnitus ringing less noticeable • Anyone building a consistent wind-down routine — same mix, same timer, every night WHY SLO? A focused sound machine, not a content platform: 150+ curated sounds, a mixer with per-layer volume, and a sleep timer. No voices, no playlists — steady sound that sits in the background while you sleep, study, or work. Slo is free to download and try; the full sound library is a premium purchase inside the app. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Terms of Service: https://meltedbutter.co/terms/noise.html Privacy Policy: https://meltedbutter.co/privacy/noise.html FREQUENTLY ASKED QUESTIONS What is the best app for brown noise? Slo is built around brown noise: play it on its own, or layer it under rain or a fan sound with a separate volume for each layer, and set a timer so it stops on its own. Does brown noise help you sleep? Brown noise doesn't treat anything — what it does is mask. A steady low-frequency sound covers unpredictable noise like traffic, doors, and snoring, which is why many light sleepers keep it running at night. Can I use Slo for tinnitus? Steady broadband sounds like brown and pink noise can help mask tinnitus ringing — many people set a low volume that makes the ringing less noticeable at night. Slo is a sound player, not a treatment; persistent or one-sided tinnitus needs a medical assessment. What are solfeggio frequencies and binaural beats? Slo includes solfeggio tones (396–963 Hz, with 432 Hz and 528 Hz), Schumann resonance tones, and binaural beats — steady tones many people play for meditation and winding down. Try one with headphones and keep it if you like it. What's the difference between brown, white, pink and green noise? White noise spreads energy evenly across all frequencies (like static). Pink noise shifts energy toward lower frequencies (like steady rain). Green noise centers on the middle of the spectrum. Brown noise goes deepest — a low rumble like a waterfall or strong wind. Slo includes all of them, so try each and keep what suits you. Can I use it for studying and focus? Yes. Many users prefer brown noise or fan noise as a steady background for studying and deep work, because a constant sound gives the ear nothing new to chase. Can I mix multiple sounds together? Yes. Layer brown noise with rain, add thunder over a fan, and set each sound's volume separately to build your own soundscape. Does Slo have a sleep timer? Yes. Set the timer when you press play and playback stops automatically. Is Slo free? Slo is free to download and try; the full 150+ sound library is a premium purchase inside the app.
Screenshots
Verdict
The clearest difference is ads: White Noise Deep Sleep Sounds at none against Slo's shown. White Noise Deep Sleep Sounds also leads on ratings volume (207K vs 63) and chart position (#96 vs unranked). Slo's advantage is update cadence (every 2 days vs monthly) and review sentiment (100% vs 83%). On price, rating, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. White Noise Deep Sleep Sounds sells 11 in-app purchases, starting at $0.99 per 7 days and Slo sells 4 in-app purchases, starting at $5.99 per month. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.8 for White Noise Deep Sleep Sounds against 4.9 for Slo. That said, the two scores are not equally well evidenced: White Noise Deep Sleep Sounds has 207K ratings behind it against 63, so its average is the more settled of the two. Written reviews are what separate them: 83% of White Noise Deep Sleep Sounds's written reviews are positive against 100% of Slo's.
White Noise Deep Sleep Sounds ships an update monthly, Slo every 2 days. The most recent releases landed on September 24, 2026 and September 15, 2026 respectively.
| Parameter | White Noise Deep Sleep Sounds | Slo |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (207K ratings) | 4.9 (63 ratings) — better |
| Positive reviews | 82.8% of reviews | 100.0% of reviews — better |
| Number of ratings | 207K — better | 63 |
| Update frequency | Monthly | Every 2 days — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Best chart rank | #96 — better | — |
| Devices | iPhone, iPad, iPod, Apple TV | iPhone, iPad, iPod, Mac |
| Requires iOS | 15.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 191 MB | 72 MB |
| Age rating | 4+ | 4+ |
| Developer | Slumber Studios, LLC | KARLIE ALEXIS KOWALSKA |
Customer experience
White Noise Deep Sleep Sounds
Slo
Bugs and requests
White Noise Deep Sleep Sounds
Reported bugs
3 issues- Sudden app crashes
- Unexpected subscription charges
- Unreliable connectivity with smart speakers
Requested features
5 requests- More free sound options
- Ability to upload custom sounds
- Independent volume control for mixed sounds
- Indefinite looping for continuous playback
- Chromecast/AirPlay support
Slo
Not enough reviews yet to summarise bugs or requests.
In-app purchases
White Noise Deep Sleep Sounds
- Premium (Weekly)3 Days trial$0.997 Days
- Premium (Weekly)3 Days trial$1.997 Days
- Premium (Monthly)7 Days trial$5.991 Month
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- Premium (Monthly)$5.991 Month
- Premium7 Days trial$19.991 Year
- Premium7 Days trial2 variants$39.991 Year
- Premium1 Month trial$39.991 Year
- White Noise Machine Premium7 Days trial$49.991 Year
- Premium (Family Sharing)7 Days trial$59.991 Year
- Continuous Play$4.99
- Everything$12.99
Slo
- Monthly Premium$5.991 Month
- Yearly Access7 Days trial$29.991 Year
- Lifetime Access$24.99
- Lifetime Access$49.99
Questions
Is White Noise Deep Sleep Sounds free?
Is Slo free?
Which has better reviews, White Noise Deep Sleep Sounds or Slo?
Do White Noise Deep Sleep Sounds or Slo have ads?
Which is updated more often, White Noise Deep Sleep Sounds or Slo?
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