What Is Brown Noise and Why Is Everyone Obsessed With It?

Somewhere around the summer of 2022, a sound that had existed since the dawn of physics became the most talked-about wellness trend on the internet. TikTok videos featuring brown noise racked up millions of views. People described it as “a warm blanket for your brain.” The ADHD community embraced it as a focus tool. Sleep forums buzzed with testimonials.

The brown noise hashtag has accumulated over 113 million views on TikTok, and Google search interest in colored noise quadrupled in 18 months following the initial viral wave.

But here’s the thing most articles won’t tell you: the science of brown noise is simultaneously fascinating, promising, and almost entirely unproven. Understanding what brown noise actually is — and what the research does and doesn’t support — puts you in a much better position to decide whether it belongs in your daily routine.

Brown Noise: The Physics

Brown noise is not named after a color. It’s named after Robert Brown, a Scottish botanist who in 1827 observed pollen particles suspended in water moving in random, erratic patterns. Albert Einstein later explained this phenomenon: microscopic particles are bombarded by surrounding molecules at an astonishing rate, producing what we now call Brownian motion.

Brown noise is the audio equivalent of that random motion. Technically, it’s generated by integrating white noise — each sample is the sum of the previous sample plus a random value. This creates a signal where power decreases as frequency increases, following a specific mathematical relationship: power is inversely proportional to the square of the frequency.

In practical terms, that means brown noise has substantially more energy in low frequencies and substantially less in high frequencies. It sounds deep, rumbly, and thick — like a heavy waterfall, strong wind, or the low roar of distant thunder.

The Noise Color Spectrum Explained

To understand brown noise, it helps to see where it sits relative to its cousins. Each “color” of noise has a different distribution of energy across the frequency spectrum.

White noise has equal power at every frequency. Imagine every note on a piano being played at the same volume simultaneously. The result is a bright, hissing sound — like television static or a running vacuum cleaner. Technically, it has a flat power spectrum with a spectral exponent of zero.

Pink noise falls off gently — power decreases by about 3 decibels per octave. This means each octave has equal energy, which our ears perceive as more balanced than white noise. Pink noise sounds like steady rainfall, a river, or wind through trees. It follows a 1/f power distribution.

Brown noise falls off much more steeply — power decreases by about 6 decibels per octave, twice the rate of pink noise. Low frequencies dominate heavily. The result is deeper and fuller than pink noise, resembling heavy surf, a strong waterfall, or rumbling thunder. Its power follows a 1/f² distribution with a spectral exponent of 2.

The audible difference is significant. White noise sounds sharp and static-like. Pink noise sounds even and natural. Brown noise sounds deep and enveloping. Many people who find white noise grating discover that brown noise feels substantially more comfortable, and the physics explains why: the high-frequency content that makes white noise feel “harsh” is dramatically reduced.

Why Brown Noise Went Viral

The brown noise explosion can be traced to a specific cultural moment. In mid-2022, a TikTok user shared that brown noise helped them manage ADHD symptoms and anxiety. The video went viral — reportedly reaching nearly ten million views within weeks. The ADHD community, already sharing coping strategies on social media, picked it up and ran with it.

What followed was a cascade effect. Listeners with ADHD described brown noise as “silencing their internal monologue” and “making their brain feel quiet for the first time.” These descriptions resonated powerfully with people who had never found an adequate way to articulate their experience of mental noise. Media outlets from Newsweek to Vogue covered the trend. Spotify and YouTube saw surges in brown noise streaming.

The appeal wasn’t just about ADHD. People without any diagnosis reported that brown noise helped them sleep, focus, and feel calmer. The low-frequency dominance seems to produce a subjective sensation of being enclosed in sound — surrounded and blanketed rather than stimulated.

What the Research Actually Says (Honest Assessment)

Here’s where the conversation gets complicated, and where most articles on this topic fail their readers.

The most rigorous research on noise and cognition comes from a 2024 meta-analysis by Nigg and colleagues, published in the Journal of the American Academy of Child and Adolescent Psychiatry. This analysis examined 13 studies with 335 total participants looking at colored noise and task performance. The researchers’ finding regarding brown noise was unambiguous: no peer-reviewed studies on brown noise were identified.

Zero. The viral sensation that millions of people use daily has not been directly tested in a single published controlled study.

What has been studied is white and pink noise, and those findings are genuinely interesting. The meta-analysis found a statistically significant small benefit for individuals with ADHD — an effect size of g = 0.249. Noise appeared to help people with attention difficulties perform better on cognitive tasks.

However, the same meta-analysis found a negative effect for individuals without ADHD — an effect size of g = –0.212. For people with typical attention, background noise slightly impaired performance.

A 2022 systematic review published in the Journal of Clinical Sleep Medicine, examining 34 studies with 1,103 participants, found no strong evidence supporting noise machines for sleep improvement — though importantly, it also found no evidence of harm.

The Arousal Theory: Why It Might Work (Especially for ADHD)

The most compelling theoretical framework comes from the Moderate Brain Arousal model. Joel Nigg, a professor at Oregon Health and Science University who led the 2024 meta-analysis, explains the underlying theory: cognitive performance follows an inverted U-curve with respect to arousal. You perform poorly when you’re drowsy and poorly when you’re panicked. Somewhere in the middle is your optimal zone.

The theory proposes that the level of external stimulation needed to reach this optimal zone varies between individuals. People with ADHD may have lower baseline dopamine signaling, which means they need more environmental stimulation to reach the same arousal level that neurotypical individuals achieve in quieter settings.

Söderlund, Sikström, and Smart published a foundational study in 2007 demonstrating this exact pattern: noise improved cognitive performance in children with ADHD while impairing it in children without ADHD. The effect was consistent across multiple cognitive measures.

This framework is well-supported for noise in general. The specific claim that brown noise works better than white or pink noise for this purpose, however, remains untested.

The Neuroscience of Low Frequencies

Even without direct brown noise studies, neuroscience offers some plausible explanations for why lower frequencies might feel particularly soothing.

Research has shown that low-frequency sounds can activate the parasympathetic nervous system, which promotes calmness and relaxation. Deep sounds — a bass note, a sustained hum, the rumble of distant thunder — tend to induce slower breathing and relaxed physiological states.

Professor Stephen Elliott of the University of Southampton has suggested that the low-frequency content of brown noise leads people to associate it with calming natural situations, like being near the ocean or in heavy rain. The random nature of the noise masks distracting environmental sounds, while the frequency profile avoids the harsh, stimulating quality of white noise.

There’s also a masking argument. Brown noise is particularly effective at covering up low-frequency environmental sounds — traffic rumble, building HVAC systems, neighbor noise through walls — because that’s where its energy is concentrated. White noise is better at masking high-frequency sounds like conversation. For many modern environments, low-frequency noise is the dominant distraction, which gives brown noise a practical advantage.

Brown Noise vs. White Noise vs. Pink Noise: Which Should You Choose?

Since research hasn’t directly compared the three colors for specific outcomes, the best guidance comes from combining the physics of each sound with the indirect evidence available.

Choose white noise if you need to mask speech, conversation, or other high-frequency distractions. Its flat spectrum covers the full audible range equally, making it the broadest masking tool. The most-studied color for sleep and focus, though many find it harsh for extended listening.

Choose pink noise if you want something natural-sounding and balanced. Pink noise most closely matches how our ears naturally perceive equal loudness across frequencies. Some sleep studies have found pink noise may enhance slow-wave sleep and memory consolidation, though results are mixed. If you like the sound of steady rain, you already like pink noise.

Choose brown noise if you prefer deeper, more enveloping sound. Its heavy bass and reduced treble make it the most comfortable for extended listening at moderate volumes. Best for masking low-frequency environmental noise, and the preferred choice among many ADHD self-advocates — though this preference hasn’t been clinically validated.

Choose nature sounds if you want the cognitive benefits of sound masking combined with the parasympathetic activation that natural soundscapes provide. Rain, ocean waves, and heavy wind share acoustic properties with pink and brown noise while adding biological recognition that pure synthetic noise lacks.

Medical professionals have been carefully measured in their statements about brown noise, which is itself informative.

A Cleveland Clinic sleep specialist has noted that brown noise has gained popularity mainly through social media testimonials, but scientists are still researching its benefits and it’s too soon to draw firm conclusions about its effectiveness.

Nigg, whose meta-analysis represents the current state of the evidence, has acknowledged that studies on ADHD and brown noise specifically are virtually nonexistent. He’s also noted that there appears to be little harm in trying it.

A Harvard Medical School sleep specialist has recommended against using any noise continuously through the night, suggesting instead that it may be useful for a set period to help with falling asleep more quickly.

The consensus position could be summarized as: probably harmless, possibly helpful, definitely not proven, and the mechanisms that would make it work are scientifically plausible.

How to Use Brown Noise Effectively

For sleep: Play brown noise at a low volume — just enough to mask environmental sounds. Set a timer for 30 to 60 minutes rather than playing it all night. Position the speaker or device away from your head, not directly beside your ear. The goal is to create an even, low-level soundscape that fades into the background as you drift off.

For focus and deep work: Use brown noise as a foundation layer, not the only sound. Layering soft instrumental music or ambient tones over brown noise can provide both the masking benefits of the noise and the mood benefits of music. Start when you begin a work session and keep it consistent — changing your audio environment mid-task creates a minor context switch.

For anxiety and overwhelm: If you’re one of the many people who find brown noise subjectively calming, use it during stressful transitions — commuting, waiting in crowded spaces, or decompressing after intense social interaction. Headphones make this practical anywhere.

Volume matters. Extended exposure to any sound above 70 decibels can potentially affect hearing over time. Brown noise for focus or sleep should be at conversation level or below — roughly 50–60 decibels, about the volume of moderate rainfall.

The Honest Bottom Line

Brown noise is a genuinely interesting acoustic phenomenon with a plausible biological mechanism, an overwhelmingly positive anecdotal track record, and virtually no direct scientific validation. That’s not a contradiction — it’s simply the current state of the evidence.

The theoretical framework supporting it is solid: noise can improve performance for people with lower baseline arousal, low frequencies activate calming physiological responses, and sound masking is well-established as a tool for reducing environmental distraction. The fact that no one has specifically studied brown noise in a controlled trial doesn’t mean it doesn’t work — it means we don’t yet have the rigorous evidence to confirm what millions of people report experiencing.

If brown noise makes your brain feel quieter, helps you sleep, or improves your focus, the current expert consensus suggests there’s no reason to stop. Just understand that you’re part of an enormous informal experiment that science hasn’t caught up with yet.

And given how science works, it will. The research is coming. In the meantime, millions of people are pressing play and finding relief — and that experience, while not a clinical trial, isn’t nothing.

→ /sounds (Sound Library — noise colors category)
→ /for-sleep (Sleep vertical)
→ /science (Research Hub — link noise research)
→ Blog 2.2: White Noise vs Pink Noise vs Brown Noise
→ Blog 2.1: Why Rain Sounds Help You Sleep
→ Blog 2.11: Best Ambient Sounds for ADHD Focus
→ Blog 2.12: Night Sounds for Deep Sleep