Guide / Updated 24 October 2026
Generated noise versus a looped recording
Generated noise is calculated continuously and does not return to the same recording point. A looped recording repeats an audio file and may have a seam or recognizable pattern. Source ↗
- Generated noise has no repeating recording point.
- A recording can sound more natural or contain recognizable events.
- The source method does not determine comfortable loudness.
How to try it
Use generated white, pink or brown noise when you want an even texture. Use a recorded fan, rain or ocean when the real-world character matters more than perfect steadiness.
- Use generated white, pink or brown noise when you want an even texture.
- Use a recorded fan, rain or ocean when the real-world character matters more than perfect steadiness..
- A well-made loop can be seamless, while generated noise can still sound poor on a small speaker.
What to consider
A well-made loop can be seamless, while generated noise can still sound poor on a small speaker. The source method alone does not decide which you will prefer.
Two ways to make a long sound
A recording captures an acoustic event, then repeats a file after it reaches the end. A producer can crossfade the seam and normalize its level so the join is hard to notice. Generated noise calculates new samples continuously instead, so no fixed recording event returns on a loop schedule.
The distinction is most noticeable in natural scenes. A raindrop, bird call or wave crest might repeat in a short recording; mathematically generated white noise has no such recognizable event, but it also lacks the character of a real place.
Listen for the problem you actually notice
If a loop seam or repeated thunder keeps catching your ear, a simple generated texture may be easier to ignore. If sterile hiss feels uncomfortable, a real fan or rain recording may be better. Compare at a gentle perceived level on the same speaker.
A high-quality loop can be more pleasant than poor synthesis, and generated audio can be distorted by a weak speaker. Neither method is a universal quality label.
Licensing matters when files are reused
SleepMix’s sound files come from documented real recordings. Its attribution file identifies sources and the two attribution-required works. This website deliberately avoids copying app audio into the browser generator, so its three noise colors do not create a new web distribution of those recordings.
If you create your own mix from outside recordings, check each license and preserve required credit. A sound being freely downloadable does not mean it is free to republish.
What “continuous” really guarantees
The worklet continues making samples while its AudioContext is allowed to run. It does not promise that a phone will keep the page active after lock, a speaker will stay connected or the battery will last all night. Test the playback route you plan to use.
Choose a timer when you only need background sound while settling. Longer generated playback still adds acoustic exposure, so a quiet level remains important.
Use the app for layers
A single generated color is good for comparing white, pink and brown. SleepMix is built for mixing multiple sound sources with individual sliders and saving a favorite combination. A layered mix can be more expressive, but it may also include elements that draw attention.
Use the free website when simplicity is the goal. Choose the iPhone app when saved recordings and a repeatable bedside setup are valuable to you.
Pick by what you hear
Play a real rain clip for a while. Can you spot a drop that comes back? Then try the free noise tool. Does its even wash help, or do you miss the feel of rain? There is no need to rank one type as best. Keep the sound you can hear at a low level and then ignore.
Common questions
Is a loop always audible?
No. A well-edited recording can repeat smoothly, though some listeners notice repeated events.
Is generated noise a recording of rain?
No. This site synthesizes colored noise; SleepMix includes separate credited recordings.
Does randomness make generated audio better for sleep?
Not by itself. Comfort and the actual interruption matter more than how samples are produced.