What Is White Noise? Listen to a Sample and Understand the Sound
Updated
White noise is a broad mixture of frequencies that often sounds like a steady hiss. People look for it to create a consistent background or make other sounds less noticeable. Understanding that texture is useful before deciding whether you want it in your room.
Hear this version
Listen for the brighter, airier quality associated with white noise. A recording of rain or a fan may sound similar, but that resemblance alone does not make it acoustically identical to white noise.
White Noise
Sample · 15 secondsChoose a sound to begin.
A 15-second preview of the sound in the app. No automatic repeat.
What do the frequencies mean?
In the ideal model, equal-width frequency bands carry equal power: a 100 Hz-wide band is compared with another 100 Hz-wide band. It is not one note at a special number of hertz, nor does every frequency sound equally loud to our ears.
The acoustic description explains the noise model; the sample is Night Light’s own version, not a laboratory reference signal.
White noise for sleep: claims and evidence
| Claim | What was actually studied | What we can conclude |
|---|---|---|
| It can cover other sounds. | Masking is one use of broadband noise; how much a sound stands out depends on the noises and their levels. [2] | Making a noise less noticeable does not remove it or prove better sleep. |
| It improves everyone’s sleep. | A 2025 meta-analysis of 12 trials found improvements in some sleep outcomes, with different populations and methodological limitations. [3] | Positive findings in particular groups do not guarantee the same result at home. |
| More noise means more benefit. | A 2021 review found mixed results and very low-quality evidence for continuous noise improving sleep. [4] | There is no reason to chase a louder setting or treat the sound as a guaranteed sleep solution. |
The practical choice is whether you like a steady, brighter background. If the hiss draws your attention instead of fading into the background, another texture—or quiet—may suit you better.
A simple way to listen
- Start with a low, comfortable volume. Listen to the texture, rather than making it loud enough to cover everything.
- After the sample ends, leave a short pause. Notice whether you prefer this background sound or the quiet.
- If you keep listening in the app, choose the duration that suits you and use the timer when you want it to stop.
A common question
Is white noise the same as noise cancellation?
No. Adding background sound can make something else less noticeable; it does not perform the same job as blocking sound or active noise cancellation. Turning the volume up is not a substitute for reducing the source of an unwanted noise.
Compare white, pink, brown and green noise →
Sources and further reading
- MathWorks · Colored Noise
- Audacity · Noise
- Ding et al. (2025) · White noise and sleep quality
- Riedy et al. (2021) · Noise as a sleep aid
Research reviewed on October 25, 2026. Results depend on the sound, volume, setting and people studied; the cited studies did not test Night Light.