Pink noise for sleep: what it is and what the research says

What pink noise actually is

Pink noise equal energy per octave; deeper and more even than white (steady rain, wind through trees). In engineering terms its spectrum falls 3 dB for every doubling of frequency, which is why it sounds balanced, like steady rain. The other two colors are shown faintly on the chart for comparison.

What the research shows

Pink noise has the most interesting research, but it is easy to overstate. The 2017 Northwestern study (Papalambros) used short pink-noise pulses timed to the brain's slow waves in thirteen older adults and found deeper slow-wave sleep and better memory the next morning. That is not the same as playing pink noise all night from a phone. The 2021 systematic review (Riedy) found the broader evidence for continuous noise weak.

How to use it tonight

Keep the level low — enough to blur a passing car, not enough to notice. Most people do better with a sleep timer than with sound running all night: once asleep, a change in sound later can wake you, and the research on all-night noise is mixed. If pink noise feels harsh, try rain recordings, which sit close to pink.