Brain.fm vs. Endel vs. Noisli: Which Is Best?
Brain.FM
Not all focus music works the same for ADHD brains.
If you've ever searched for "best focus music app" or tried to find background sounds that actually help you concentrate, you've probably encountered three names: Brain.fm, Endel, and Noisli. They all promise to help you focus—but they work in fundamentally different ways.
Here's the thing most comparison articles won't tell you: only one of these apps has been tested in peer-reviewed neuroscience research and shown to provide greater benefits for people with attention difficulties. If you have ADHD—or even just struggle to maintain focus—that distinction matters.
This isn't a superficial feature comparison. We're going to examine the actual science behind each approach, what the research says about effectiveness, and help you determine which app is genuinely the best focus music app for your brain.
Three Fundamentally Different Approaches to Focus Audio
Before diving into the details, it's worth understanding that these three apps represent entirely different philosophies about how sound can support concentration:
Neural Entrainment (Brain.fm): Uses patented technology to embed specific amplitude modulations in music that synchronize with brain activity to enhance focus
AI-Adaptive Soundscapes (Endel): Generates personalized ambient sounds that adapt in real-time based on your circadian rhythm, heart rate, weather, and time of day
Manual Sound Mixing (Noisli): Provides a library of ambient sounds (rain, coffee shop, white noise) that you mix yourself to create a pleasant background environment
These aren't just different features—they're different theories about what makes focus audio effective. Let's examine each one.
Brain.fm: Neural Phase-Locking and Brainwave Entrainment
Brain.fm's approach is built on a specific neuroscience mechanism: neural entrainment. The idea is that rhythmic external stimuli can influence the brain's internal electrical rhythms, guiding them toward states associated with focus, relaxation, or sleep.
How It Works
Brain.fm embeds precise amplitude modulations—typically 10-20 modulations per second for focus music—directly into musical compositions. These modulations are designed to elicit "neural phase-locking," where the brain's electrical activity synchronizes with the audio stimulus.
This is different from binaural beats, which require headphones and produce relatively weak effects. Brain.fm's patented approach modulates the audio signal directly in each stereo channel, creating stronger entrainment effects that work with any audio playback system.
The Research
Brain.fm's technology has been tested in collaboration with Northeastern University's MIND Lab (Music, Imaging, and Neural Dynamics Laboratory), led by Dr. Psyche Loui, with funding from the U.S. National Science Foundation.
In October 2024, the results were published in Communications Biology (a Nature journal). The study, "Rapid modulation in music supports attention in listeners with attentional difficulties," used behavioral tests, fMRI brain imaging, and EEG recordings to examine how Brain.fm's modulated music affects attention.
Key findings:
Beta-range amplitude modulations (12-20 Hz) improved sustained attention performance
Participants with higher ADHD symptoms showed greater benefits from the modulated music
fMRI revealed increased activation in the salience network, executive control network, and sensorimotor network
EEG confirmed strong stimulus-brain coupling at target frequencies
Practical Features
Large music library: Thousands of tracks across genres (lo-fi, classical, electronic, ambient, nature sounds)
Adjustable neural effect: Low, medium, and high intensity settings (with a "boost" option for ADHD users)
Multiple modes: Focus, Relax, Sleep, Meditation
Pomodoro timer: Built-in productivity timer
Offline playback: Download tracks for use without internet
Pricing: $14.99/month(7-day free trial) or $99.99/year (14-day free trial)
Endel: AI-Adaptive Soundscapes
Endel, founded in Berlin in 2018, takes a different approach: instead of embedding specific neural modulations, it uses AI to generate ambient soundscapes that adapt to your personal context in real-time.
How It Works
Endel's patented "Endel Pacific" engine generates soundscapes based on multiple inputs:
Circadian rhythm: Time of day and your body's natural energy cycles
Heart rate: Via Apple Watch or other wearables
Weather: Local conditions via location data
Motion: Movement speed for activity modes
Time of day: Adjusts intensity throughout the day
The result is generative audio that's technically never the same twice. Endel won Apple Watch App of the Year in 2020 and has partnerships with artists like James Blake and Grimes.
The Science
Endel claims its soundscapes are based on "neuroscience and psychoacoustic principles," including circadian rhythm research and the effects of sound on heart rate and arousal levels.
A 2021 study by Arctop (a neurotechnology company) claimed Endel provides a "7x increase in focus." However, this study was not published in a peer-reviewed journal, making it difficult to evaluate the methodology or compare it to independent research.
Endel's approach is grounded in real principles—circadian rhythms do affect alertness, and heart rate variability is linked to stress—but the specific claims about focus enhancement haven't been validated through the same rigorous peer-review process as Brain.fm's research.
Practical Features
Endless, adaptive soundscapes: Never repeats exactly
Multiple modes: Focus, Relax, Sleep, Move
Scenarios: Timed sessions for specific activities (Deep Work, Study, Read)
Artist collaborations: Soundscapes with James Blake, Grimes, Miguel, and others
Wide platform support: iOS, Android, Apple Watch (standalone), Apple TV, Alexa, web
Pricing: $14.99/month, ~$50/year, or ~$90 lifetime (7-day free trial)
Noisli: Simple Ambient Sound Mixing
Noisli, launched in 2013, takes the simplest approach: it provides a library of high-quality ambient sounds that you mix yourself to create your ideal background environment.
How It Works
Noisli offers 16 ambient sounds—including rain, thunder, wind, forest, ocean, coffee shop, train, and white/pink/brown noise—with individual volume sliders. You layer and adjust these sounds to create custom "combos" that you can save and replay.
There's no AI, no neural modulation, and no adaptive technology. Noisli is essentially a high-quality sound mixer designed to mask distracting noises and create a pleasant acoustic environment.
The Science
Noisli doesn't claim any proprietary neuroscience technology. Instead, it relies on well-established principles of sound masking—the idea that consistent background noise can reduce the disruptive impact of sudden sounds (like coworker conversations or traffic) by making them less noticeable.
This is legitimate science. Research consistently shows that unpredictable noise spikes are more disruptive to concentration than steady background sound. But sound masking is a different mechanism than active cognitive enhancement—it reduces distraction rather than boosting focus.
Practical Features
16 high-quality sounds: Nature, urban, and noise options
Custom combos: Save your favorite mixes
Timer: Built-in Pomodoro-style timer with fade-out
Text editor: Minimal distraction-free writing space
Offline playback: Download sounds for offline use
Simple interface: Clean, intuitive design
Pricing: Free tier available; Premium at $12/month or $120/year
The Science: What Does Research Actually Say?
This is where the comparison gets interesting—and where the differences really matter.
Peer-Reviewed Research
Brain.fm: Published in Communications Biology (Nature, October 2024). This is a peer-reviewed journal, meaning the study was evaluated by independent scientists before publication. The research used multiple methodologies (behavioral tests, fMRI, EEG) and was funded by the National Science Foundation.
Endel: References a 2021 study by Arctop claiming "7x focus increase," but this has not been published in a peer-reviewed journal. The methodology and data are not publicly available for independent evaluation.
Noisli: Makes no claims of proprietary neuroscience research. Relies on general principles of ambient sound and noise masking, which are well-established but not specific to the app.
ADHD-Specific Evidence
This is particularly relevant if you struggle with attention:
Brain.fm: The Woods et al. (2024) study specifically found that participants with higher ADHD symptom scores showed greater benefits from the modulated music. The 16 Hz modulation in particular was associated with improved attention in high-ADHD-symptom participants.
This aligns with the "optimal stimulation theory" of ADHD—the idea that ADHD brains are "under-aroused" and require more external input to reach the activation level needed for focused performance. A 2024 meta-analysis by Oregon Health & Science University confirmed that auditory stimulation (white/pink noise) provides measurable cognitive benefits for ADHD individuals while slightly impairing non-ADHD performance.
Endel: Mentions ADHD support in marketing materials but has no published research demonstrating differential effects for people with attention difficulties.
Noisli: No ADHD-specific claims or research, though general noise masking research suggests it can help with distraction reduction.
Head-to-Head Comparison
Here's how the three apps compare across key dimensions:
Core Technology
Brain.fm: Patented neural phase-locking via amplitude modulation
Endel: AI-generated adaptive soundscapes based on biometric/environmental inputs
Noisli: Manual ambient sound mixing for noise masking
Peer-Reviewed Research
Brain.fm: Yes (Communications Biology, Nature, 2024; NSF-funded)
Endel: No (company-commissioned study, not peer-reviewed)
Noisli: No proprietary research; relies on general sound masking principles
ADHD-Specific Benefits
Brain.fm: Research-proven greater effects for high-ADHD-symptom users; adjustable intensity
Endel: Marketing mentions ADHD; no specific research
Noisli: No ADHD-specific features or claims
Personalization
Brain.fm: Genre selection, neural effect intensity, activity modes
Endel: Automatic adaptation to heart rate, weather, time, motion
Noisli: Manual mixing of individual sounds
Music Library
Brain.fm: Thousands of tracks across multiple genres; new music added weekly
Endel: Generative (endless but limited variety); can feel repetitive over time
Noisli: 16 ambient sounds to mix
Pricing
Brain.fm: $14.99/month or $99.99/year
Endel: $14.99/month, ~$50/year, or ~$90 lifetime
Noisli: Free tier; Premium $10/month or $120/year
Which Is Best for ADHD Brains?
If you have ADHD—or simply struggle with sustained attention—the research points clearly to Brain.fm.
The Woods et al. (2024) study didn't just show that Brain.fm's modulated music improves focus generally. It specifically demonstrated that people with higher ADHD symptom scores benefit more from the technology than neurotypical users.
This aligns with decades of research on ADHD and auditory stimulation. The ADHD brain is often "under-aroused," meaning it requires more external input to reach optimal cognitive performance. Brain.fm's amplitude modulations appear to provide exactly this kind of targeted neural stimulation.
Brain.fm also offers practical features for ADHD users:
Adjustable neural effect intensity: Including a "boost" setting for users who need more stimulation
No song changes: Continuous audio streams eliminate the novelty response that can distract ADHD brains
Large variety: Thousands of tracks prevent the boredom that often plagues ADHD users
Built-in Pomodoro timer: Supports time-boxing strategies that work well for ADHD
The Bottom Line: Which Should You Choose?
Choose Brain.fm If:
You have ADHD or significant attention difficulties
You want peer-reviewed, scientifically-validated focus technology
You need deep focus for demanding cognitive work (writing, coding, studying)
You prefer variety in your focus music (multiple genres)
You want the option to adjust the neural effect intensity
Choose Endel If:
You want a fully automated, "set and forget" experience
You're interested in circadian rhythm-based adaptation
You use Apple Watch and want wearable integration
You prefer ambient soundscapes to structured music
You value artist collaborations and aesthetic design
Choose Noisli If:
You primarily need to mask distracting background noise
You want complete control over your sound environment
You prefer simplicity over advanced features
You want a free option to try ambient sounds
You're looking for a basic tool rather than a focus enhancement system
The best focus music app depends on what you actually need. For simple noise masking, Noisli works fine. For ambient adaptation, Endel is interesting. But if you want the best focus music app with proven cognitive benefits—especially if you have ADHD—Brain.fm is the clear choice.
When it comes to your brain, the difference between "feels focused" and "actually focused" matters. Choose the app that can prove it works.
Ready to experience neuroscience-backed focus? Try Brain.fm free and feel what patented neural phase-locking can do for your concentration.
Sources & References
Primary Research:
Woods, K.J.P., Sampaio, G., James, T., Przysinda, E., Cordovez, B., Hewett, A., Spencer, A.E., Morillon, B., & Loui, P. (2024). Rapid modulation in music supports attention in listeners with attentional difficulties. Communications Biology, 7, 1376. https://doi.org/10.1038/s42003-024-07026-3
Nigg, J.T., et al. (2024). Systematic Review and Meta-Analysis: Do White Noise or Pink Noise Help With Task Performance in Youth With Attention-Deficit/Hyperactivity Disorder?Journal of the American Academy of Child & Adolescent Psychiatry. Oregon Health & Science University.
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.
Additional Sources:
NSF STTR Phase I Grant #1720698: "Remediating Inattention with Algorithmically Generated Music" (2017-2018)
Endel Official Website and Technology Documentation (endel.io)
Noisli Official Website (noisli.com)
Arctop Study (2021) - Referenced in Endel marketing; not peer-reviewed