White noise

White noise is the most effective masker in the library because its energy is spread evenly across the frequency range. Whatever noise is bothering you, part of the white noise sits on top of it. That is why it remains the standard recommendation for open-plan offices, noisy streets and thin walls.

Its weakness is the same as its strength. Perfectly even and completely unchanging, it can feel clinical over long sessions, and some people find it fatiguing after an hour or two. The usual fix is not to turn it down but to soften it: a layer of rain adds organic variation without adding anything that demands attention.

Volume matters more here than anywhere else. Set it just above the sound you are trying to cover and no higher — the goal is a uniform floor you stop noticing, not a wall of sound. If you are still aware of it after ten minutes of work, it is too loud.

Use it alone when the room is genuinely noisy, and blended with rain when you just want a stable bed to work over.