Why fan noise works
A fan produces broadband noise weighted toward the low-mid range, with a faint tonal hum from the motor. That combination masks a wide range of everyday sounds without the sharp top end of pure white noise, which is why so many people find it easier to sleep to. It is also completely steady: no rhythm, no changes, nothing for the brain to follow.
The ShiftSleep Fan generator models those qualities. The AC generator is a cousin with a broader, airier hum. Both are procedural, so unlike a recording of a fan there is no point at which the sound restarts.
Fan noise in the mixer
Fan is a free-tier generator. Play it alone or, in the mixer, set it as one layer and add Brown Noise beneath it for extra low-end coverage of traffic and footsteps. If the fan feels too mechanical, swapping to Pink Noise plus Fan gives a softer, more natural bed. Each layer has its own level, mute and solo.
- Fan — steady mechanical whir with a low hum
- AC — air-conditioner broadband hum
- Layer with Brown, Pink or White Noise, Rain or Ocean
- Sleep timer with soft fade-out; all-day option
- Two-second soft start on every play
- No loop, no ads, no connection needed
Fan noise for day sleep after a night shift
Shift workers reach for fan noise because it is familiar and forgiving: it sounds like a normal bedroom, not like a sound effect. ShiftSleep AI adds the parts a fan cannot do — a timer that fades, a shift profile that knows your sleep window, one-tap logging of day sleeps and recovery naps, and an AI helper that can suggest a fan-based mix for your rota.
Free to start
Free includes Fan, the color noises, a two-layer mixer, the sleep timer and one shift profile. Premium unlocks the full catalog, four layers, unlimited saved mixes and the AI helper, billed through Apple or Google.
ShiftSleep AI supports rest and routine with sound and simple logging. It is not medical advice and does not diagnose or treat sleep disorders. If your sleep problems persist, talk to a clinician.
Frequently asked questions
Does the fan sound loop?
No. It is generated live, so it is a continuous sound with no seam.
Can I make the fan sound deeper or brighter?
Layer it. Add Brown Noise for more depth or White Noise for more brightness, and set each level independently in the mixer.
Will it drain my battery overnight?
Audio generation is lightweight compared with streaming or video, but any all-day playback uses some battery. Plugging in for long sessions is sensible.