Fan noise for sleeping: what the research shows

A steady fan sound may help some people sleep by covering up other noises, but research hasn't shown that continuous noise improves sleep in general. Two systematic reviews found the evidence weak, and neither review looked at fans specifically. If you like the sound, try it for a few nights and judge by your own sleep. This guide is for adults.

What the research says

The Riedy review. Riedy and colleagues at the University of Pennsylvania reviewed 38 studies of continuous white noise or similar broadband noise and sleep (Sleep Medicine Reviews, 2021). The authors describe the findings as "with the extremes being that continuous noise improves or disrupts sleep". Studies differed in the noise used, how sleep was measured and what the control condition was. Using the GRADE criteria, the authors rated the quality of evidence that continuous noise improves sleep as "very low", which they note "contradicts its widespread use". They also wrote that continuous noise may negatively affect sleep and hearing, and asked for more research before it's promoted as a sleep aid.

The Capezuti review. Capezuti and colleagues looked at 34 studies with 1,103 adults in total, covering white noise, pink noise and mixes of sounds. Nineteen studies reported better sleep outcomes. The authors still concluded there was "no strong evidence" that it helps. No study reported adverse effects with short-term use.

One small lab study on masking. In 2005 Stanchina and colleagues recorded the sleep of five people with polysomnography. Four of them also slept through recorded intensive care unit noise with white noise added. Their average arousal index that night was 15.7 per hour, close to the 13.3 of a baseline night, against 48.4 on the night with ICU noise alone. The authors' explanation is that white noise shrinks the gap between the background and the sudden peaks that wake you. It's five people in a lab, with ICU sounds, so it says little about your bedroom.

What this means for a fan

• The reviews covered white and pink noise, and neither looked at fans specifically. Treat the results as a hint, not a test of fans.
• The masking idea is plausible: a constant sound makes sudden ones less jarring. The ICU study supports it in a narrow setting.
• A benefit for everyone isn't established, and the Riedy review raises the possibility that noise makes things worse for some people.

A cautious way to try it

This part is practical advice, not a finding from the studies.

1. Pick a sound you find calm, not just loud enough to cover the noise.
2. Keep the volume low. The Riedy review flagged hearing, so the quietest level that covers what bothers you is a sensible starting point.
3. Use a timer so it doesn't play all night, if you don't need it to.
4. Try it for a week and compare how you sleep. If you sleep worse, stop.
5. If you struggle to sleep most nights, talk to a clinician. A sound isn't a treatment.

Real fan or a fan recording

A real fan makes the sound and also moves air, which some people want in summer and some don't. A recording gives you only the sound, with control over volume and a timer, and no cord or blades in the room.

Using Fan Noise

Fan Noise plays recordings of fans on iPhone. It isn't a sleep tracker, and it makes no health claims. It's a way to run the experiment above.

1. Pick a sound. On the player, tap "Change sound". Classic Ceiling Fan, Modern Tower Fan and Window Box Fan are free. Industrial Fan and Quiet Breeze are Premium.
2. Set the volume with the slider on the player, then press play.
3. Set the fade-out, then start the "Sleep timer". The "Fade-out" menu sets how long the sound takes to taper at the end: 30 seconds, 1, 2 or 5 minutes. Then tap 15m, 30m, 1h or 2h, which starts the timer with that fade-out.
4. Lock your phone. The sound keeps playing, with play and pause on the Lock Screen.

It works offline, because the sounds are stored in the app. There are no ads and no account. The sound also pauses during a phone call, because iOS interrupts audio for calls.

This guide shares published research for general information. It isn't medical advice and it doesn't diagnose or treat any sleep condition.