The thought of sleeping in a completely silent room gives me an unparalleled amount of anxiety. For as long as I can remember, I’ve been someone who requires the lull of a whirring fan to help me fall — and stay — asleep.

There’s something about the gentle humming sound that trumps just about any lullaby — and I know there are many people out there who vehemently agree with me. However, it wasn’t until recently that I became aware of the science behind my dependency.

The power of white noise

The main reason we rely on a trusty fan to get a good night’s sleep is less about temperature and more about white noise. White noise essentially works to mask the difference between background sounds and “peak” sounds (such as an ambulance siren or a door slamming) to maintain more consistency in your environment.

According to the National Sleep Foundation, white noise can be a game changer for light sleepers, because it gives them a chance to sleep through the night. White noise creates a constant ambient sound that reduces disturbances such as a floorboard creaking or a dog barking, peak sounds that would be disruptive to an otherwise undisturbed slumber.

The role of “sleep spindles”

So what causes fan enthusiasts to typically be categorized as light sleepers, while there are others who could sleep through road traffic, construction work, or perhaps a category one hurricane? It all comes down to differences in brain wiring, and more specifically, sleep spindles.

According to the American Psychological Association (APA), sleep spindles are brief bursts that wax and wane rapidly, producing visible spikes on electroencephalogram (EEG) tests — these spikes (or spindles) are how sleep spindles got their name.

The more sleep spindles someone experiences, the better defense they have against intrusive, outside noise.

According to research published in Cell Press, the more sleep spindles someone experiences, the better defense they have against intrusive, outside noise, which is why people who rely on fans to sleep often have a lower production of sleep spindles in their brains.

Sleep spindles occur during rapid eye movement (REM) sleep, which takes place toward the end of the night (between the sixth and eighth hours of sleep, according to the APA) and is crucial to replenishing neurotransmitters in the brain. The regeneration of these neurotransmitters is essential in a healthy brain that is capable of learning, remembering, performing and problem solving.

“Sleeping fewer than six hours may block sleep spindles and stop new information from entering long-term memory, which helps acts such as a golf swing become automatic,” James B. Maas, PhD, a professor and former chairman of the psychology department at Cornell University told the APA.

Why do some people produce more sleep spindles than others?

According to HowStuffWorks, there’s no definitive answer as to why some people produce a plentitude of sleep spindles (and thus are luxuriously deep sleepers), while others are spindle-deprived light sleepers, devoted to fans in order to create a consistent, sound sleeping environment.

However, if it’s the lull of your trusty fan and its subsequent white noise that has worked for you so far, there’s no reason to change your routine. Plus, it helps create a cooler overall environment, which is proven to be effective in boosting sleep hygiene. Sweet dreams, fan devotees.

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Bonus: 8 signs your sleeplessness is something more serious

Sometimes sleeplessness (though frustrating) can be remedied in natural ways, such as reducing caffeine consumption, becoming aware of late night snacking habits or limiting screen time before bed. Other times, though, sleep issues can be more serious, evolving into full blown chronic insomnia. Here are the warning signs.

  1. Daytime fatigue or sleepiness.
  2. Difficulty socializing.
  3. Poor concentration and focus.
  4. Irritability, depression, or anxiety.
  5. Being uncoordinated, an increase in errors or accidents.
  6. Tension headaches (ie. the feeling of a tight band around the head).
  7. Gastrointestinal symptoms.
  8. Worrying about/dreading sleeping.