fan noise

what does this fan sound like?

like a desk fan on a medium setting in the next room: a soft rush of air with most of its weight in the low and middle range, a faint flutter from the blades, and a motor hum you only notice if you listen for it. it sits somewhere between brown noise and pink noise, with a little more texture than either.

how is it made?

there is no recording. your browser builds the sound live from two kinds of generated noise: a deep layer that is filtered to keep only the lows, and a lighter band of hiss on top for the moving air. a quick, shallow flutter in the level stands in for the blades, and two quiet tones play the part of the motor. since nothing loops, there is no seam to catch at three in the morning. it is the same fan as the one in the sound mixer, where you can layer it with rain or a fireplace.

how loud should a fan sound be?

quiet enough that you could still hear someone talking to you. the US Centers for Disease Control and Prevention says sounds at or below 70 decibels are unlikely to cause hearing loss even over long periods, and a background sound for sleep has no reason to get near that. start with the slider low.

can you leave it on overnight?

it keeps playing in a background tab and stops when you leave this page. the stop timer under the slider switches it off after 30 minutes, an hour, two hours or eight. for what research does and doesn't say about steady sound and sleep, see does brown noise help you sleep better.