White Noise for Sleep: When It Helps and How to Use It

White noise is the most studied sleep sound, and the most misunderstood. A 2021 study found it helped people in noisy NYC apartments fall asleep faster, but a systematic review concluded it had "little beneficial effect" overall. And a 2026 Penn Medicine study found broadband noise (including white) reduced REM sleep by nearly 20 minutes per night. Here's when white noise actually helps, when it hurts, and how to use it without damaging your sleep quality.

White noise contains equal energy across all audible frequencies, from 20 Hz to 20,000 Hz. It sounds like TV static, a loud fan, or a rushing air vent. The name comes from an analogy with white light, which contains all visible wavelengths.

Here's the thing most people don't realize: that hissing quality that makes white noise distinctive is also what makes some people hate it. The equal energy across all frequencies means the high-pitched content is just as loud as the low-pitched content. That's why pink noise and brown noise sound softer to most ears: they reduce those high frequencies.

But that high-frequency content is exactly what makes white noise the strongest masker. If your main sleep problem is noise, white noise covers the widest range of disruptive sounds.

Sound Masking: The Primary Mechanism

The main evidence-backed benefit of white noise for sleep is masking. Your brain processes sounds even during sleep. Sudden, sharp noises (a door closing, a siren, a partner's snore) trigger brief arousals that fragment your sleep, even if you don't fully wake up.

White noise works by raising the "noise floor" in your room. When there's a consistent background sound, the relative difference between that background and a sudden disruption shrinks. A car horn at 2 AM is jarring in silence. Over white noise, the same horn is much less noticeable.

A 2021 study of adults living in high-noise NYC environments found that white noise machines helped participants fall asleep faster. Hospital studies from the 1990s and 2000s showed similar results: patients in noisy ICU wards slept better with continuous white noise.

I've found this is the key distinction most articles miss: white noise doesn't improve your sleep. It prevents bad sleep from getting worse. If you already sleep in a quiet room, adding white noise probably won't help and might actually hurt (more on that below).

When White Noise Works Best

White noise is a strong choice if:

• You live near a busy road, train line, or airport
• Your partner snores or moves around at night
• You're in a dorm, apartment, or hotel with thin walls
• You work night shifts and sleep during daytime noise
• You travel frequently and need consistent sleep conditions

White noise probably won't help if:

• Your sleep environment is already quiet
• Your main problem is racing thoughts or anxiety (that's a nervous system issue, not a noise issue)
• You find the hissing quality irritating

The 2026 Penn Medicine Study

In February 2026, Dr. Mathias Basner at the University of Pennsylvania published a study in the journal Sleep that tested broadband noise at 50 dB over 7 consecutive nights with 25 adults. The results challenge the idea that sleep sounds are universally helpful.

Key findings:

• Pink noise reduced REM sleep by about 19 minutes per night. White noise, as another broadband sound, carries the same risk.
• Aircraft noise alone cut about 23 minutes of N3 deep sleep per night.
• Combining noise with broadband masking increased wakefulness by 15 minutes compared to sleeping in quiet.
• Earplugs outperformed broadband noise at protecting sleep from environmental disruption.

Dr. Basner was direct about the implications: "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."

What I found surprising: the masking sound that people use to protect their sleep may itself be disrupting a different stage of sleep. You're trading environmental noise disruption for broadband noise disruption. The question is which tradeoff makes sense for your situation.

The Systematic Review Problem

A systematic review published in Sleep Medicine Reviews concluded that white noise had "little beneficial effect on sleep" when you look across all available studies. The individual positive studies are mostly small (under 50 participants), short-term (1-3 nights), and conducted in labs or hospitals rather than real bedrooms.

Let me be direct: the evidence for white noise improving sleep is weaker than most people think. The evidence for white noise masking noise in loud environments is stronger. Those are different claims, and the distinction matters.

This is the section most white noise articles handle poorly, so I want to be specific.

What the Research Shows

White noise machines have been used in nurseries for decades. Some research shows white noise can help infants fall asleep faster and may reduce crying episodes. A study found white noise "may reduce heart rate and respiratory rate, effectively lulling an individual to sleep."

But there are real safety concerns.

The AAP Warning

A 2014 study from the American Academy of Pediatrics tested 14 popular infant white noise machines. Every single one exceeded the hospital's recommended noise limit of 50 dB when placed near a crib at maximum volume. Some reached levels above 85 dB, which can damage hearing over time.

Dr. Basner's 2026 study specifically warned about children: developing brains spend more time in REM sleep than adult brains. If broadband noise reduces REM, the impact on infants and toddlers could be larger than on adults.

Safe Use for Babies

If you use white noise for your baby:

1. Place the machine across the room, at least 7 feet from the crib. Never inside or directly next to the crib.
2. Use the lowest volume that masks disruptions. Well under 50 dB at the crib.
3. Set a timer. Don't run it all night. Let it play during the initial sleep-onset period (30-60 minutes), then turn off.
4. Consult your pediatrician, especially for premature babies or those with hearing concerns.

The trap to avoid is assuming that because white noise "works" for sleep, more is better. Volume and duration both matter.

This comparison is the most common question, and I think most guides make it more complicated than it needs to be.

My recommendation: If you need maximum noise blocking (busy street, snoring partner, thin apartment walls), white noise is the most effective masker. If comfort matters more and your noise problem is moderate, pink noise or rain sounds will feel more pleasant. If you find both white and pink noise too "hissy," try brown noise.

For a full breakdown of every sleep sound type, see our sleep sounds guide.

Based on the combined research, here is the protocol I'd recommend:

Volume

Keep it under 50 dB. Use a free decibel meter app on your phone to check. For reference, 50 dB is roughly the volume of a quiet conversation. If you can easily talk over it, you're in the right range. If you have to raise your voice, it's too loud.

The WHO recommends environmental noise below 40 dB at night for healthy sleep. Your white noise should be just above whatever disruptions you're trying to mask, not cranked to maximum.

Duration

Don't play it all night. This is the biggest change from old advice.

Set a 30-60 minute timer. The sleep-onset period (falling asleep) is when masking helps most. Once you're in deep sleep, your arousal threshold rises and you're less sensitive to noise anyway. Running white noise for 8 hours straight means 7+ hours of unnecessary broadband exposure that may be reducing your REM sleep.

Dr. Rafael Pelayo from Stanford's Division of Sleep Medicine recommends this approach: "Play it at a low volume, and set a timer so it's not playing through the night."

Device Placement

Place the sound machine across the room, not on your nightstand. Distance naturally reduces the volume at your ears and provides more even sound distribution. Under-pillow speakers and earbuds put sound directly into your ear canal, which raises the effective volume significantly.

Consider Earplugs

Here's what most people miss: if your main goal is blocking environmental noise, the 2026 Basner study found earplugs were more effective than broadband noise. Earplugs reduce incoming sound without adding new sound. They protect all sleep stages equally.

If I had to pick one approach for someone in a noisy environment, I'd recommend trying earplugs first. They're cheaper, simpler, and don't carry the REM risk. If earplugs are uncomfortable or you can't tolerate them, then white noise with a timer is the next best option.

If you've been using white noise and still aren't sleeping well, the noise isn't your issue. Here's what I've noticed: most people who reach for white noise are actually dealing with one of these:

Racing mind at bedtime. White noise masks external sounds but does nothing for internal noise. If your thoughts are keeping you awake, you need active nervous system regulation, not passive sound masking. A guided NSDR protocol walks your nervous system through a deliberate downshift that white noise can't provide.

Inconsistent sleep schedule. No amount of ambient sound compensates for going to bed at different times every night.

Screen exposure before bed. Blue light suppresses melatonin regardless of what's playing on your sound machine.

Stress-driven insomnia. This is a dysregulated nervous system, not an environmental noise problem. NSDR (Non-Sleep Deep Rest) targets this directly with structured body scans and breathing protocols that shift your body from sympathetic (fight-or-flight) to parasympathetic (rest-and-digest) mode.

The takeaway is: white noise is a tool for one specific problem (environmental noise disruption). If your sleep problems go deeper, try a free NSDR track to actively regulate your nervous system before bed. Many people find 10 minutes of guided regulation more effective than 8 hours of background noise.

Is white noise safe to play all night?

Based on the 2026 Penn Medicine study, I'd recommend using a timer instead. Continuous broadband noise at 50 dB reduced REM sleep across 7 nights. Use white noise to fall asleep (30-60 minute timer), then let your brain sleep in quiet.

Does white noise help with tinnitus?

Many people with tinnitus find white noise helpful for masking the ringing, especially at night. The broad frequency range means it can cover a wider range of tinnitus frequencies than pink or brown noise. Talk to an audiologist for a personalized recommendation, as the optimal sound depends on your specific tinnitus profile.

Is a fan the same as white noise?

Close, but not identical. A fan produces mostly low-to-mid frequency sound, more similar to pink or green noise than true white noise. But a fan provides good enough masking for most situations and has the added benefit of air circulation. If a fan works for you, there's no need to switch to a dedicated white noise machine.

Can you become dependent on white noise for sleep?

There's limited research on dependency, but anecdotal reports are common. Some people find they can't sleep without their sound machine after years of use. This is likely a learned association rather than a physical dependency. If it concerns you, try using white noise only a few nights per week rather than every night.

What volume should white noise be for sleep?

Under 50 dB at your listening position. Use a decibel meter app to check. If you're using it for a baby, keep it well under 50 dB at the crib and place the device at least 7 feet away. The goal is just enough volume to smooth out disruptions, not to fill the room with sound.