About Rakuno'Oto
Rakuno'Oto
Free Ambient Sound Mixer for Focus & Relaxation
Discover the science and story behind focus music.
Mix rain, campfire, white noise, ocean waves——
Combine 9 types of ambient sounds to create
your own perfect background music.
Try It Now — Free
No signup required · 100% free · Works in your browser
ABOUT
What is Rakuno'Oto?
Rakuno'Oto is a free ambient sound mixer web app that lets you blend 9 types of environmental sounds—rain, brown noise, white noise, streams, city ambience, campfire, ocean waves—and loop them seamlessly. We also offer premium packs with instruments and extra sounds for added variety.
All processing happens in your browser. No data is sent to external servers. No installation needed—anytime, anywhere, create your own private "audio sanctuary" in seconds.
FEATURES
Why Rakuno'Oto Stands Out
Simple yet thoughtfully designed. All the features
you need for focus, relaxation, and sleep—completely free.
Mix & Match
Blend 9 types of ambient sounds at any volume. With multiple variations, the combinations are limitless.
1/f Fluctuation
Natural rhythm patterns found in nature. Campfire and ocean waves fluctuate beautifully, just like the real thing.
Spatial Audio
With headphones, sounds surround you in 3D space. Rain from above, campfire in front. Includes a "lying down mode" for comfort.
Save Presets
Save your favorite mixes with custom names. Share them across devices or with friends using a share code.
Browser-Based
No app download needed. Access instantly on any device, anytime, anywhere from your browser.
Privacy-First
Audio processing happens entirely in your browser. Only preset settings are temporarily stored on our server when using share features.
Timer & Pomodoro
Built-in Pomodoro timer for work-break cycles. Also works as a regular timer with customizable alarms.
Breathing Exercises
Guided breathing techniques (4-7-8 and 4-4-8) are designed to support relaxation practices.
Sync & Share
Connect with other listeners in real-time and share the same ambient mix. A gentle way to feel less alone.
SOUNDS
Available Ambient Sounds
9 carefully curated environmental sounds, from natural to noise.
Multiple variations of each for fine-tuned control.
City Ambience
6 variations
Instruments
Lo-fi piano & more (7 premium)
Extras
Footsteps, crickets & more (6 premium)
HOW TO USE
How to Use & Tips
Rakuno'Oto is designed to be simple. In just 3 steps, you can create your own perfect sound space.
Timer & Pomodoro
The timer controls are on the left side (bottom on mobile). Use the sleep timer to auto-start or auto-stop playback, or switch between work and break cycles with the Pomodoro timer.
3 Simple Steps
1
Pick a sound and adjust the volume
Choose from rain, brown noise, white noise, stream, city ambience, campfire, ocean waves, instruments, and extras. Drag the slider to set the volume. Mix multiple sounds together. (Instruments and extras are premium.)
2
Switch between variations
Each sound has multiple variations. Tap the small button in the upper right of each channel to switch variations and explore different moods of the same sound.
3
Press play
Hit the central play button to start seamless looping. Use the master volume slider to adjust overall loudness.
1/f Fluctuation — Natural, Soothing Sound Variation
"1/f fluctuation" is a rhythm pattern found in nature: the strength of a breeze, the gentle variation of a babbling stream, the flicker of a candle flame. It's neither purely random nor perfectly regular—it's just the right kind of pleasant variation. You can apply 1/f fluctuation to each sound channel in Rakuno'Oto.
①
Toggle per channel
Tap the 1/f button next to each channel name. The sound will gently fluctuate. Tap again to turn it off.
②
Adjust "fluctuation strength"
Use the strength slider below the master volume to set the range from 0-100. Lower values create subtle waves; higher values create more dramatic changes.
Tip: Setting fluctuation strength to 0 automatically disables 1/f. It pairs beautifully with campfire and ocean waves, adding a natural, immersive quality. Try starting around 20-40.
Spatial Audio — Immersive 3D Sound with Headphones
Spatial audio uses Web Audio API's HRTF (Head-Related Transfer Function) so sounds seem to come from specific directions when you wear headphones. Rain falls from above, campfire flickers in front, city sounds surround you—each sound feels like it's coming from the right place.
Below the fluctuation strength slider, tap the "Spatial Audio" button to choose from 4 levels.
①
Choose OFF / Weak / Medium / Strong
OFF is regular stereo. Weak to Strong increase the 3D effect and spatial width. Start with Weak or Medium to get a feel for it.
②
Put on headphones and listen
Spatial audio only works with headphones or earbuds. Speakers won't give you the effect, so please use headphones to experience the full immersion.
Tip: Rain at spatial audio "Medium" or higher feels like you're standing in the rain itself. Combine it with 1/f fluctuation for an even more natural, comforting experience.
Lying Down Mode
Tap the bed icon at the right end of the spatial audio button to switch to "lying down mode."
Normal spatial audio is based on a sitting posture, but lying down mode recreates the acoustic experience of being on your back. Rain falls onto your face, campfire and waves feel like they're coming from your feet——all adapted for maximum relaxation while lying down.
It works with any spatial audio level (weak, medium, strong), making it perfect for pre-sleep relaxation.
Breathing Exercises — Guided Relaxation
Rakuno'Oto includes a guided breathing mode that is designed to support relaxation. Just follow the on-screen visual guide and choose from two breathing techniques.
1
Choose a breathing technique
The 4-7-8 technique is better for deep relaxation. The 4-4-8 technique is gentler if breath-holding feels uncomfortable.
2
Select a duration
Choose from 1, 3, or 5 minutes depending on your mood.
3
Breathe along with the guide
Follow the light ring and text on screen to inhale, hold, and exhale. A progress bar appears during the hold phase so you know how much time is left.
Tip: Using breathing exercises while ambient sounds play creates a deeper relaxation experience. Pair it with rain or brown noise. Breathe at your own pace—don't push yourself.
Important: If you have concerns about your heart, lungs, or blood pressure, or if you're pregnant, please consult a doctor before doing breathing exercises. If holding your breath feels uncomfortable, stop immediately. These exercises are for relaxation only and are not a substitute for medical treatment.
Saving and Loading Presets
Save any mix you love as a preset. Tap the save button (floppy disk icon on the left) and give it a name. Load it anytime from the load button (folder icon on the right). Your 1/f fluctuation settings and sound variations are saved too.
MIXING TIPS
Tips for a Pleasing Mix
With Rakuno'Oto's sliders, you can create endless soundscapes. Here are some tips for crafting a mix that feels truly pleasant.
1. Environmental Sounds as the Foundation
The base of your mix should be environmental sounds: rain, brown noise, or streams. Start with 1-2 main sounds at a comfortable volume. You'll be surprised at how much comfort an ambient foundation alone can provide.
2. Barely Audible Sounds Add Depth
Layer very quiet sounds beneath your main mix. For example, add just a whisper of city ambience or ocean waves under rain. These sounds add invisible depth and texture——they're not noticeable on their own, but when removed, the mix feels thin. This is the "air layer" that makes a mix feel complete.
3. Instruments Should "Just Suggest"
A beautiful ambient space is all about environmental sounds. If you add instruments, keep them very low. Crank them up too high and it stops being ambient——your mind locks onto the melody. The sweet spot is barely hearing the notes, like they're peeking through from far away. That subtlety is what makes them special.
4. 1/f Fluctuation Brings the Mix to Life
Fixed volume sliders can make loop recordings feel mechanical and repetitive. Turn on 1/f fluctuation and the mix "breathes." It shifts naturally and feels alive. This works especially well with campfire and ocean waves. Experiment starting around 20-40 strength to find your comfort zone.
Summary: "Environmental sound base, barely-there layers for depth, instruments whisper softly, and let 1/f add natural breathing." There's no right answer. Find your own "just right" sound.
SYNC
Gently Connected
Rakuno'Oto has a gentle connection feature that lets you feel linked to others listening right now.
Press "Connect with Someone's Mix" and you'll sync with someone else listening somewhere in the world. You're not in the same place, but you're listening to the same sounds——a quiet, simple kind of connection.
You can send a "thank you" to the person you're connected with. A gentle visual appears on their screen too.
You never know who connected with you. No counts, no notifications, no history, no leaderboards. This isn't social media competition or a dopamine chase——it's designed to stay simple and wholesome.
A quiet but real connection that exists only in this moment. That's how Rakuno'Oto connects people.
Privacy: This feature temporarily sends your current mix settings (volumes, sound selections, etc.) to our server. It doesn't include any personally identifying information, and the data is automatically deleted within minutes.
USE CASES
Perfect For
Focused Work & Study
Cafe bustle or brown noise blocks distractions and helps you concentrate at the office or home.
Better Sleep
Gentle loops of rain or ocean waves ease you into natural sleep. Lying down mode is ideal.
Deep Relaxation
Mix campfire with streams and your home becomes a cozy getaway——pure relaxation.
Block Out Noise
White noise masks chatter and background sounds. Great for cafes, trains, and open offices.
Works on phones and tablets too.
Access it on any iPhone, iPad, or Android device through your browser. Note: Due to browser limits, background playback (with screen off) is not supported. Keep the window open to keep listening.
PREMIUM
Premium Sounds
All core features are completely free. We also offer optional premium packs to unlock additional sounds.
Buy Once, Use Forever: No monthly fees. Pay once and keep the sounds permanently.
How to Purchase
Tap any sound with a lock 🔒 icon to open the purchase screen. Choose individual packs ($1.99 each) or unlock everything ($7.99). Stripe handles payment, and your sounds unlock instantly.
Use on Multiple Devices
Access your purchased sounds on any device—your home PC, work computer, phone, tablet, etc.
1
Enter your email during purchase
Use the email address in the Stripe payment screen. This is your key to restoring your purchases.
2
On a new device, tap "Already Purchased?"
Open Rakuno'Oto on your new device and tap the "Already Purchased?" button in the premium modal.
3
Restore with your email
Enter the email you used at purchase. You'll get a confirmation code. Enter it and all your sounds unlock on that device.
Tip: Clearing your browser cache or cookies may reset your purchase data. Don't worry——just follow the steps above to restore everything easily.
RESEARCH
Environmental Sounds & Focus — What Research Shows
Scientists have been researching how white noise and ambient sounds affect focus and relaxation. Here's what some of that research tells us.
Important Disclaimer: This is general research about environmental sounds. Rakuno'Oto itself hasn't been formally studied, so we can't guarantee the same effects. Think of this as interesting background knowledge, not medical claims.
Inattention and Noise
Meta-Analysis: White & Pink Noise Effects
A 2024 systematic review and meta-analysis in the Journal of the American Academy of Child & Adolescent Psychiatry found that white and pink noise tend to improve cognitive performance in people with attention difficulties. However, people without attention challenges showed slight decreases, suggesting effects are individual.
Source: Nigg, J. T., Bruton, A., Kozlowski, M. B., Johnstone, J. M., & Karalunas, S. L. (2024).
JAACAP, 63(8). DOI:
10.1016/j.jaac.2023.12.014
Stochastic Resonance Model
Söderlund, Sikström, and Smart (2007) explained inattention using "stochastic resonance"——a physics concept. When focus is hard, your brain's baseline arousal is low (understimulated). The right amount of external noise stimulates your nervous system to optimize weak signal detection, boosting attention. In other words, noise temporarily "fills a stimulation gap."
White Noise and Memory Performance
In a 2010 study, Söderlund, Sikström, and Loftesnes found that children with attention challenges improved their episodic memory while listening to 78 dB of white noise. In contrast, children with strong attention saw performance dip. This shows that noise effects depend heavily on individual differences in focus ability.
Source: Söderlund, G., Sikström, S., & Loftesnes, J. M. (2010).
Behavioral and Brain Functions, 6, 55. DOI:
10.1186/1744-9081-6-55
Natural Sounds and Stress Relief
Natural Sounds Speed Stress Recovery
Alvarsson, Wiens, and Nilsson (2010) exposed stressed subjects to either natural sounds (fountains, birdsong) or traffic noise. The group with natural sounds showed faster drops in stress markers (skin conductance) than the traffic noise group. This shows nature sounds promote physiological recovery from stress.
Source: Alvarsson, J. J., Wiens, S., & Nilsson, M. E. (2010).
International Journal of Environmental Research and Public Health, 7(3), 1036-1046. DOI:
10.3390/ijerph7031036
Sound Interventions & Stress: A Broad Review
A 2025 scoping review in JMIR Mental Health examined sound interventions (nature, music, white noise) for adult stress. Multiple studies show natural environmental sounds positively affect cortisol and autonomic nervous system markers.
Source: Rieiro, H., et al. (2025).
JMIR Mental Health. DOI:
10.2196/69120
Sleep Quality
White Noise and Sleep Quality (Meta-Analysis)
A 2025 meta-analysis of randomized controlled trials published in Sleep found that white noise significantly improved PSQI (Pittsburgh Sleep Quality Index) scores in adults and older adults. In infants, it lengthened sleep duration and reduced awakenings. White noise masks sudden environmental sounds, creating a steady acoustic environment that promotes sleep.
Broadband Noise and Sleep Onset Speed
Messineo et al. (2017) studied a transient insomnia model and found that broadband noise significantly shortened sleep onset latency in healthy adults. Noise appears to mask fluctuating environmental sounds, easing the transition to sleep.
Reality Check: These effects are statistically real but modest in size. Results vary by person——noise can backfire for some. Long loud listening can hurt hearing. Use a volume that feels comfortable and take breaks. Rakuno'Oto is not a medical device and doesn't treat illness.
Why Meaningless Sound Feels So Good
Researchers have identified three main reasons why ambient sounds and noise help focus and relaxation.
1. Optimal Arousal Theory
When focus is hard, your brain's resting arousal is low——you feel bored. White and brown noise provide just enough stimulation to bump you into the "Goldilocks zone" of alertness, where focus comes easier.
2. Auditory Masking
Noise with defined frequency bands covers up sudden sounds (conversation, notifications, household noise). This shields your attention and lowers cognitive load.
3. Neural Optimization
Some researchers propose that broadband noise affects how your brain's neurons communicate, supporting sustained focus. The stochastic resonance model suggests external noise optimizes the brain's signal detection.
STORY
The Story Behind It
Rakuno'Oto was created by Haruki Tominaga, a designer based in Japan.
"I've always struggled to maintain focus. Silence is too distracting, but music with lyrics or melody hijacks my attention. Then I discovered 'meaningless sounds'——white noise, brown noise, natural ambient sounds. I tried existing apps, but none let me create the exact balance I wanted, simply and freely. So I built Rakuno'Oto——shaped by the Japanese sense of 'ma' (the beauty of space and silence) and a deep respect for nature's rhythms.
The name Rakuno'Oto comes from Japanese: 'raku' (comfort, ease) and 'oto' (sound)——a place where sound brings you peace. That's the spirit."
NOTICE
Important Information
Please review the following to use Rakuno'Oto safely and responsibly.
Recommended Environment
Rakuno'Oto is designed primarily for comfortable use on a desktop browser. Phones and tablets work too, but browser limitations (no background playback, autoplay restrictions, etc.) mean the experience may not be identical to desktop. A dedicated mobile app is in early planning stages with no launch date yet.
Disclaimer: Rakuno'Oto is a relaxation and focus aid, not a medical device or therapy. If you have health concerns, please consult a professional before use.
About Sounds
Audio files may be updated, replaced, or adjusted without notice to improve quality. Please understand this may happen.
Outdoor Use
When listening outdoors with earbuds or headphones, ambient noise may be blocked. Please stay aware of traffic and your surroundings for safety.
Long-Term Listening
Listening at high volume for extended periods may affect your hearing. When using headphones or earphones, please listen at a comfortable, moderate volume and take occasional breaks. Steady sounds such as white noise and brown noise can provide more continuous auditory stimulation than natural sounds, so please adjust use according to how you feel.
References
- Söderlund, G., Sikström, S., & Smart, A. (2007). Listen to the noise: Noise is beneficial for cognitive performance in ADHD. Journal of Child Psychology and Psychiatry, 48(8), 840-847.
https://doi.org/10.1111/j.1469-7610.2007.01749.x
- Nigg, J. T., Bruton, A., Kozlowski, M. B., Johnstone, J. M., & Karalunas, S. L. (2024). Systematic Review and Meta-Analysis: Do White Noise or Pink Noise Help With Task Performance in Youth With ADHD? Journal of the American Academy of Child & Adolescent Psychiatry, 63(8).
https://doi.org/10.1016/j.jaac.2023.12.014
- Söderlund, G., Sikström, S., & Loftesnes, J. M. (2010). The effects of background white noise on memory performance in inattentive school children. Behavioral and Brain Functions, 6, 55.
https://doi.org/10.1186/1744-9081-6-55
- Alvarsson, J. J., Wiens, S., & Nilsson, M. E. (2010). Stress Recovery during Exposure to Nature Sound and Environmental Noise. International Journal of Environmental Research and Public Health, 7(3), 1036-1046.
https://doi.org/10.3390/ijerph7031036
- Messineo, L., et al. (2017). Broadband sound administration improves sleep onset latency in healthy subjects in a model of transient insomnia. Frontiers in Neurology, 8, 718.
https://doi.org/10.3389/fneur.2017.00718
- Impact of white noise on sleep quality across age groups and in critically ill/non-critically ill patients: A systematic review and meta-analysis of randomized controlled trials. Sleep (2025).
https://doi.org/10.1016/j.sleep.2025.106869
- Rieiro, H., et al. (2025). Effects of Sound Interventions on the Mental Stress Response in Adults: Scoping Review. JMIR Mental Health.
https://doi.org/10.2196/69120
- Noise as a sleep aid: A systematic review. Sleep Medicine Reviews, 55 (2021), 101385.
https://doi.org/10.1016/j.smrv.2020.101385
FAQ
Frequently Asked Questions
Q.
Is it really free?
Yes, Rakuno'Oto is completely free to use. No signup or login required. We offer optional premium sound packs if you want extras.
Q.
Do I need to download an app?
No. It runs entirely in your browser. Just visit the URL and start using it immediately——no installation needed.
Q.
Can I use it on my phone or tablet? Does it support background playback?
Yes, you can use it on iPhone, iPad, Android, and other devices through the browser. However, due to browser limitations, background playback (playing with the screen off) is not currently supported. A dedicated app is in early planning stages but has no launch date yet.
Q.
I can't hear sound on my phone or tablet.
First, check that Silent Mode (mute switch) is OFF——iOS in particular mutes browser audio when muted. If you came from a bookmark, try tapping play after the page loads. If still silent, refresh the page and check that your volume sliders and master volume aren't at zero.
Q.
Is my data sent to external servers?
Audio processing stays entirely in your browser. Only when you use the "Connect with Someone" feature does any data go to our server——specifically your mix settings (volumes, sound choices, etc.) for syncing. No personal information is sent.
Q.
My saved presets disappeared on Safari.
Safari (on iPhone, iPad, and Mac) includes a privacy feature called ITP (Intelligent Tracking Prevention) that automatically deletes browser-stored data after 7 days of inactivity on a site. To protect your favorite presets, we recommend using the "Export Presets" feature to back them up as a share code.
Q.
Will you keep updating and improving it?
Yes. Updates happen irregularly but consistently.
Q.
Can I request new sounds or features?
Direct requests aren't possible (we can't respond to all messages), but we do pay attention to what people say about Rakuno'Oto on social media. Your feedback helps shape development.
Q.
Can I use it as background music for streaming?
Our terms don't allow using it as plain background music for streams. However, if your stream is primarily about introducing Rakuno'Oto, we'd love that!
Q.
What are premium sounds?
Beyond the core 7 sounds, we offer instrument packs and extra sound packs. Buy individual packs ($1.99 each) or unlock everything ($7.99). It's a one-time purchase——no monthly fees.
Q.
I entered the wrong email when I bought premium sounds.
Your purchase stays on that device, but you won't be able to restore it on another device. Please contact us via the support form with your purchase details. We can look it up in Stripe, but it may take time.
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