White noise generator
Sound generated in your browser · nothing downloaded or streamed
Three kinds of noise, generated in the page rather than streamed. White is flat across all frequencies and sounds hissy; pink falls off with frequency and sounds like rain; brown falls off faster and sounds like a waterfall or distant traffic.
How to use the noise generator
The colours are precise terms, not marketing. White noise has equal power at every frequency, which puts a great deal of energy in the high range where hearing is most sensitive; hence the hiss. Pink noise drops 3 dB per octave, giving equal power per octave, which is much closer to how natural sounds are distributed and why it sounds like rain. Brown drops 6 dB per octave and is dominated by the low end. For masking speech through a wall, pink or brown works better than white, because speech energy is low and mid-range and covering it with hiss just adds a second thing to hear.
Questions
Equal energy per frequency, per octave, and a steeper low-frequency slope. In practice: hissy, rain-like, and waterfall-like.
Most people prefer pink or brown for long listening. White has a lot of high-frequency energy that becomes fatiguing.
Almost none. The noise is generated by your browser, so nothing streams after the page has loaded.
Usually not. Mobile browsers suspend audio from a background tab; a dedicated app is better for overnight use.
At a low volume, generally yes. Keep it quiet: sustained loud noise near the ears overnight is not harmless.
Because it is generated fresh rather than looped from a recording. That is why there is no audible repeat.