Pink noise has become one of the most popular sounds people use to sleep, focus, and manage stress. But a 2026 study from Penn Medicine found it may reduce REM sleep by nearly 20 minutes a night. Here's what the research actually supports, what the risks are, and how to use pink noise the right way.
What Is Pink Noise? The Quick Version
Pink noise is a broadband sound where lower frequencies carry more energy than higher ones. Think of rain hitting a roof, wind rustling through trees, or a distant waterfall. It sounds deeper and warmer than white noise because of this bass-heavy balance.
The technical name for this pattern is "1/f noise," meaning each octave carries equal energy. In practice, that means the high-pitched hiss you hear in white noise gets dialed down, and the low rumble gets turned up. The result is a sound most people describe as more natural and less grating than pure white noise.
Here's the thing: most articles about pink noise either oversell the benefits or ignore the recent research that complicates the picture. I've found the reality sits somewhere in the middle, and the details matter more than most sources let on.
How Pink Noise Affects Sleep
Deep Sleep Enhancement
The most cited research on pink noise and sleep comes from Northwestern University. In a 2017 study, Dr. Phyllis Zee's team played precisely timed bursts of pink noise synchronized to participants' slow brain waves during deep sleep. The result: a threefold improvement in word recall the next morning.
Dr. Zee explained the mechanism: "The effectiveness of pink noise is all in the timing. The effect here, at least for memory, is quite related to the ability of the sound stimulus to enhance slow-wave sleep."
That's a real finding, but I'd caution against reading too much into it. The study had only 13 participants, all older adults, tested over two nights in a lab. It used precisely timed sound bursts (not continuous pink noise from a speaker), and the memory test was a specific word-pair task, not general cognitive performance.
A 2012 study from China found continuous pink noise did increase deep sleep duration and sleep spindle density. But again, small sample and lab conditions.
Memory and Cognitive Function
The memory link is interesting but narrower than most articles suggest. The Northwestern studies found that pink noise specifically enhanced slow-wave oscillations, which are tied to memory consolidation during sleep. A follow-up study in 2019 showed similar effects in patients with mild cognitive impairment.
What I've learned from reviewing this research: the memory benefits only showed up when the pink noise was timed to match the brain's own slow waves. Playing continuous pink noise through a speaker all night is a fundamentally different protocol, and we don't have strong evidence that approach works the same way.
The REM Problem: What the 2026 Study Found
This is where it gets interesting, and where most pink noise articles fall behind the research.
In February 2026, Dr. Mathias Basner at the University of Pennsylvania published a study in the journal Sleep that tested pink noise across 7 consecutive nights with 25 adults. At 50 decibels (roughly the volume of a quiet conversation), pink noise reduced REM sleep by about 18.6 minutes per night.
That's significant. REM sleep is when your brain consolidates emotional memories, processes the day's experiences, and supports mood regulation. Losing nearly 20 minutes of it every night adds up.
Dr. Basner put it directly: "REM sleep is important for memory consolidation, emotional regulation and brain development, so our findings suggest that playing pink noise and other types of broadband noise during sleep could be harmful, especially for children whose brains are still developing and who spend much more time in REM sleep than adults."
The same study found that aircraft noise alone cut about 23 minutes of N3 deep sleep per night, and that combining pink noise with environmental noise actually increased wakefulness by 15 minutes compared to quiet conditions.
Here's what most people miss about this study: earplugs outperformed pink noise at protecting sleep from environmental noise. If you're using pink noise mainly to block sounds, earplugs might be the better choice.
Pink Noise for Focus and ADHD
Sleep gets most of the attention, but the focus research is honestly more convincing.
The ADHD Connection
A 2024 meta-analysis from Oregon Health & Science University (OHSU) looked across 13 studies with 335 participants and found that white and pink noise improved cognitive task performance in children and young adults with ADHD or significant ADHD symptoms. The effect size was small but statistically meaningful (g = 0.249, p < .0001).
What I found surprising: the same analysis showed that noise actually hurt performance in people without ADHD (g = -0.212, p = .0036). So pink noise for focus is not a universal tool. It specifically helps people whose brains need more stimulation to maintain attention, a concept called stochastic resonance.
If you have ADHD or suspect you do, pink noise during work is worth trying. If you don't, you might be better off with silence or very low-volume brown noise, which some people find less distracting.
General Focus Use
For people without ADHD, the evidence for pink noise improving focus is thin. There's some research suggesting that consistent background sound can help maintain attention in noisy environments by masking sudden disruptions. But the mechanism there is masking, not enhancement.
If your workspace has unpredictable noise (construction, roommates, traffic), pink noise at a low volume can help by smoothing out those sharp interruptions. The key word is low volume. At higher levels, the research suggests it becomes a net negative for concentration.
Pink Noise vs. White Noise vs. Brown Noise
This comparison comes up constantly, and I think the usual articles make it more confusing than it needs to be.
| Feature | Pink Noise | White Noise | Brown Noise |
|---|---|---|---|
| Frequency balance | Bass-heavy, softer highs | Equal across all frequencies | Very bass-heavy, minimal highs |
| Sounds like | Rain, wind, waterfall | TV static, fan hiss | Thunder, heavy waterfall |
| Best for sleep | Possible deep sleep boost (with caveats) | Strong masking in noisy environments | Limited research, anecdotal preference |
| Best for focus | ADHD populations | Noisy office masking | Calming, some focus use |
| Research quality | Moderate (small studies, mixed recent data) | Moderate (most studied noise color) | Weak (very few controlled studies) |
| Perceived comfort | Most find it natural | Some find it harsh | Very soothing for most |
Best for most people: Pink noise if you want something natural-sounding for sleep or have ADHD. White noise if your main problem is a loud environment. Brown noise if you find white noise too harsh and want deep bass.
For something softer with a narrower frequency range, green noise sits between pink and brown and some people find it the most calming of all.
Is Pink Noise Safe? Real Risks to Know
Let me be direct about the safety picture, because this is where most guides gloss over real concerns.
Volume Matters More Than You Think
The Penn Medicine study used 50 decibels, roughly the volume of a quiet conversation. Even at that moderate level, it disrupted REM sleep. Most phone apps and sound machines can easily push past 70-80 dB, especially through headphones.
Dr. Rafael Pelayo from Stanford's Division of Sleep Medicine offered practical advice: "Play it at a low volume, and set a timer so it's not playing through the night."
I'd recommend keeping pink noise under 50 dB. A good rule of thumb: if you have to raise your voice slightly to talk over it, it's too loud. If it's barely louder than background room tone, you're in the right range.
Children and Infants
This is the biggest concern raised by the 2026 research. Dr. Basner specifically warned against using broadband noise for newborns and toddlers, whose brains spend significantly more time in REM sleep than adults. A separate 2014 study from the American Academy of Pediatrics found that all 14 tested infant white noise machines exceeded hospital safety recommendations when placed near a crib at maximum volume.
If you use any noise for a child's sleep, keep the device across the room (at least 7 feet away), use the lowest effective volume, and don't run it all night.
Long-Term Use
No study has followed pink noise users for months or years. The concern, raised by Basner, is that continuous sound exposure prevents the auditory system from recovering during sleep. Your inner ear translates sound into nerve signals constantly, generating metabolites that may be harmful. Without quiet periods, that recovery doesn't happen.
The trap to avoid is treating pink noise like a permanent fixture. Use it when you need it, give yourself nights without it, and pay attention to whether your sleep quality changes over time.
How to Use Pink Noise the Right Way
Based on what the research supports, here is the protocol:
For Sleep
- Volume: Keep it under 50 dB. Use a free decibel meter app on your phone to check.
- Duration: Set a 30-60 minute timer. Don't play it all night. The sleep-onset period is when masking helps most.
- Device placement: Across the room, not on your nightstand or under your pillow.
- Consider alternatives: If your main goal is blocking noise, earplugs are more effective and don't carry the REM risk.
For Focus
- Volume: Low, around 40-50 dB. It should fade into the background, not demand your attention.
- Duration: Play during the work session, typically 60-90 minutes for optimal focus blocks.
- Test your response: If you have ADHD traits, pink noise may help. If not, try it for a week and track whether your output actually improves.
- Source quality: Use a dedicated app or high-quality recording. Looped audio with noticeable repeating patterns becomes distracting once your brain detects the cycle.
For Stress Reduction
Pink noise shows promise for cortisol reduction, though the research is preliminary. The University of Minnesota Morris found listening to pink noise lowered elevated cortisol levels, and a broader review in JMIR Mental Health found sound interventions had positive effects on HRV and self-reported anxiety.
If I had to pick one approach for stress, I'd combine pink noise at low volume with a guided NSDR protocol. The sound provides the masking and the protocol gives your nervous system a structured path to downshift. That combination targets the problem from two angles rather than relying on passive listening alone.
When Your Nervous System Needs More Than Background Sound
Pink noise is a passive tool. It can mask disruptive sounds and it may support certain sleep stages, but it doesn't actively guide your nervous system into a recovery state.
That's where structured protocols make a difference. NSDR (Non-Sleep Deep Rest) is a guided approach that walks your body through a deliberate downshift: from a stressed, activated state to a calm, parasympathetic one. Research on the parasympathetic response shows that guided body scans and breath protocols activate the rest-and-digest system more reliably than passive sound alone.
The takeaway is: if you're reaching for pink noise because you can't shut your brain off, pink noise addresses the symptom (environmental noise) but not the cause (a dysregulated nervous system). A 10-minute NSDR track paired with low-volume pink noise covers both.
Explore the NSDR guided track library to see how structured rest compares to passive sound. Many people find the guided approach gets them to a calm state faster than sound masking by itself.
Frequently Asked Questions
Is pink noise better than white noise for sleep?
It depends on your situation. Pink noise may enhance deep sleep quality based on limited research, but the 2026 Penn Medicine study found it reduces REM sleep. White noise has stronger evidence for masking environmental sounds. If noise disruption is your main issue, white noise or earplugs may be the safer choice.
Can pink noise help with tinnitus?
There's some evidence. The "Pink Sound Protocol" used in clinical settings has shown promise for tinnitus management, and a 2023 literature review in PMC found positive results. Pink noise's bass-heavy profile can partially mask tinnitus frequencies. Talk to an audiologist before relying on it as a primary treatment.
Is it safe to play pink noise all night?
Based on current research, I wouldn't recommend it. The Basner study showed that even moderate-volume pink noise disrupted sleep architecture over 7 nights. Dr. Pelayo's recommendation of using a timer is the safer approach. Let it play for 30-60 minutes as you fall asleep, then let your brain sleep in quiet.
What volume should pink noise be?
Under 50 dB for sleep, 40-50 dB for focus. Use a free decibel meter app to check. For reference, 50 dB is about the volume of a quiet conversation. If you can easily talk over it, you're in the right range. For infants and children, even lower, and always with the device placed across the room.
Does pink noise improve memory?
The Northwestern University studies from 2017 showed memory improvements when pink noise was timed precisely to slow-wave sleep oscillations. But that's a very specific protocol (not just playing continuous noise), with small sample sizes, in controlled lab settings. The effect hasn't been replicated at scale in home environments.