What white noise is
White noise1 is random sound with equal power at every frequency, from the lowest rumble to the highest hiss. The name borrows from white light, which mixes every color. To the ear it sounds like a bright, even shhh: a radio between stations, a TV with no signal, air rushing from a vent.
Because our ears are most sensitive between about 2,000 and 5,000 Hz (the equal-loudness curves2 show this), white noise sounds sharper than its flat spectrum suggests. That brightness is exactly why some people like it (it covers voices and clatter well) and why others find it harsh after a while.
How to use this generator
- Press play. The sound starts at once. Nothing is downloaded: it’s made by your browser as it plays.
- Set the volume low. Start lower than you think and raise it until distracting sounds fade into the background.
- Soften it if it’s too bright. Tap Pink noise or Brown noise and lower the white slider. A little pink under white keeps the masking and loses the hiss.
- Set a timer or share. The sleep timer stops it after up to an hour, fading out. Share mix copies a link that opens your exact mix.
What people use white noise for
- Masking voices and noise. A steady sound makes sudden ones (a door, a conversation, traffic) less noticeable, because the jump in loudness is smaller. This effect, called auditory masking3, is the main, well-understood reason it helps.
- Sleep. Many people sleep better with a constant sound, especially in noisy cities or shared homes. See white noise for sleep for settings that work.
- Focus. It hides office chatter and household noise. A 2024 meta-analysis found white and pink noise gave a small boost on attention tasks to people with ADHD, and a small drop to people without it 4. More on white noise for studying.
- Privacy. A white noise source near a door makes conversations in a room harder to overhear.
- Babies. Parents often use it for naps. Keep it quiet and away from the crib: see the questions below.
White noise or something deeper?
If white noise feels sharp, you’re not alone. Most people who use noise every day settle on something softer:
| Sound | How it sounds | Try it for |
|---|---|---|
| White noise | Bright, even hiss | Blocking voices, short sessions |
| Pink noise | Softer, like steady rain | All-day focus, sleep |
| Brown noise | Deep rumble, like a distant waterfall | Sleep, deep focus, low-pitched noise |
| Fan | White noise with a gentle hum | People used to sleeping with a fan |
The side-by-side guide white noise vs brown noise explains the difference, and what is white noise? goes further into the science.
Mixes to try
Why it plays without gaps
Many white noise sites and apps play a short recording on repeat, and you can hear the seam when it loops. MoodNoise makes the noise in your browser, so it never repeats in a way you can notice. It also means the page loads quickly and works offline once you’ve visited.
Keep it quiet. Background sound works at a low level: about as loud as a soft shower or a quiet conversation across the room. If you have to raise your voice over it, turn it down. For comparison, the workplace limit NIOSH recommends is 85 decibels averaged over 8 hours 5; background sound should be far below that. For sleep, lower is better, and keep phones and speakers away from your pillow.
Sources
- Wikipedia. White noise. en.wikipedia.org.
- Wikipedia. Equal-loudness contour. en.wikipedia.org.
- Wikipedia. Auditory masking. en.wikipedia.org.
- Nigg JT, Bruton A, Kozlowski MB, Johnstone JM, Karalunas SL (2024). Systematic review and meta-analysis: Do white noise or pink noise help with task performance in youth with ADHD or with elevated attention problems?. Journal of the American Academy of Child and Adolescent Psychiatry 63(8):778–788.
- National Institute for Occupational Safety and Health (CDC) (2024). Noise-induced hearing loss. cdc.gov.
Questions
Is this white noise generator free?
Yes. Every sound, the mixer, a sleep timer up to an hour and share links are free with no sign-up or ads. MoodNoise Pro ($5 for 30 days or $29 a year) adds longer timers, an alarm, saved mixes, playback with your phone locked and downloads.
Does white noise help you sleep?
Many people find a steady sound makes it easier to fall and stay asleep, mostly because it masks sudden noises. But a 2021 systematic review rated the evidence that continuous noise improves sleep as very low quality, so it isn’t a treatment for sleep problems. If you sleep badly most nights, talk to a doctor.
Is white noise safe for babies?
Use care. A 2014 study in Pediatrics tested 14 infant sound machines at full volume: at 30 cm, all of them were louder than the 50 dB limit recommended for hospital nurseries, and three passed 85 dB. A 2026 sleep-lab study in adults found broadband noise reduced REM sleep, and its lead author advised caution for newborns and toddlers. If you use it, keep the speaker across the room, the volume low, use a timer, and ask your pediatrician.
Can I play white noise all night?
Yes. The free timer stops it after up to an hour with a fade; Pro adds timers of any length with longer fades. Keep the volume low for long listening.
Why does white noise sound so harsh?
Your ears are most sensitive between about 2 and 5 kHz, and white noise has as much energy up there as anywhere. Pink or brown noise put less energy in the highs, so they sound softer at the same loudness.
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