Why We Like to Sleep Cool With the Fan On

Sometimes it’s not enough to have the best comfy mattress when you’re trying to sleep. Room fans have become a popular way for both parents and children to lull themselves into sleep. The soothing noises are a sleep magnet — sometimes even more than the best comfy mattress. Take Shelly Betts, for example, an executive assistant in Atlanta who used the tactic on herself before realizing that it worked great with her children. She was recently featured on the popular website and podcast, “How Stuff Works.”

“The minute they heard that humming sound come on, it helped to put them to sleep a lot easier,” she says in an email. “The little things that would wake other people’s children up at night, mine never heard. The only bad drawback is they sort of need it to sleep. The nights they don’t have one they struggle.”

So why does this noise work better than the best comfy mattress? What is happening in the brain with white noise sleepers? It turns out that their brains may be wired just a little bit differently. It has to do with how the brain processes sound, a feature that is vital to the sleep process.

Sleep Spindles

It turns out that the reason white noise works for sleep is tied up in the idea of sleep spindles, basically little short wave brain bursts that happen as we drift off to sleep. Sleep spindles originate from a part of the brain known as the thalamus, which is what processes all sights and sounds in our brain. When we experience white noise, it actually blocks the thalamus from experiencing other disturbances at night, leaving the brain free to drift off to sleep. It’s a sort of trickery that scientists are still trying to fully understand.

“People who sleep with a fan are capitalizing on what we call white noise. Just like white light, which encompasses all the colors on the spectrum, white noise encompasses all sound frequencies within typical human hearing,” explains Kelsey Allan, a sleep scientist. “Technically, true white noise is generated only electronically, but ambient noises like fans, distant cicadas, or gentle rain can produce a similar effect.”

Scientists still aren’t sure why some people have better sleep spindles than others, but it’s not stopping them from trying. Sleep science is now a multi-billion dollar industry, with tons of tech money being funneled into new and exciting research for tools to help us sleep — not just the best comfy mattress, but in high tech ways like apps and sleep machines. With a sleep epidemic currently affecting the United States – most adults report getting less than the prescribed seven to nine hours of optimal sleep – now more than ever is the time to grapple with this problem

While this is all very exciting, it’s nice to know that the low tech option, namely a fan and your best comfy mattress can compete with even the most high tech options that sleep science is putting out there. So go ahead, turn on your fan and sleep peacefully. Your brain will thank you for it.