September 6, 2019
Finding the right “sleep noise” can mean better sleep for years to come, according to researchers, Real Simple reports. But you have to know what type—or specifically what color of noise—lulls you into a dream state.
White noise-a machine-generated sound that contains all frequencies—gets the most attention from sleep experts. Using a white noise machine, a white noise app, or a white noise fan man improve your sleep dramatically. But if it doesn’t, don’t give up. There are other sleep noises out there that may offer you superior benefits.
“There’s been a lot of confusion about what white noise is,” says Sam Nicolino, a sound engineer, musician, and founder of Adaptive Sound Technologies (ASTI), the Silicon Valley-based firm behind the LectroFan and Sound+Sleep series of sound machines promising a better night’s rest.
The phrase white noise has come to be broadly applied to all sorts of background noise, but white noise is actually a carefully constructed sound. It doesn’t occur in nature—it’s purely a mathematical construct, Nicolino told Real Simple. Many sounds are similar to white noise, but they’re not quite the same.
The sound can be very staticky. “For most people, it’s very unpleasant,” Nicolino says—so if you tried a white noise machine and truly disliked it, you’re not alone or out of options.
The sleep benefits from white noise don’t come from the sound itself; they come from the sound’s ability to mask other disturbances.
“When you don’t have a sleep machine, every little noise that occurs in your sleep environment has the potential of rousing you,” Rafael Pelayo, MD, a clinical professor in Stanford University’s Sleep Medicine Division, National Sleep Foundation board member, and long-time ASTI adviser, told the news outlet. “Having a pleasing background sound can prevent you from hearing these little disruptive noises.”
White noise is popular because it’s uniform, but what happens when you can’t stand white noise? It may be time to check out pink noise or brown noise.
Pink noise is white noise with fewer high frequencies.
To create pink noise, Nicolino says sound engineers take white noise and filter out high frequencies. “Pink noise sounds kind of like rain,” he says. Like white noise, though, pink noise isn’t exactly like any noise from nature. Listening to a rainfall sound machine isn’t pink or white noise—it’s simply ambient sound recording on a loop.
Sometimes called Brownian noise, Brown noise is white noise stripped of more high frequencies; it consists of lower frequencies than even pink noise.
“Brown noise can sound like a really uneventful ocean surf,” Nicolino told the magazine. It has more bass notes than white noise, making it more pleasant to listen to. And, unlike white and pink noise, brown noise is named for Robert Brown, who discovered Brownian motion (which creates the sound) in 1827, Dr. Pelayo says. (For the grammatically compulsive, this is why Brown noise is often capitalized.) “People seem to prefer the lower-toned sounds,” Dr. Pelayo says.
Most sound machines—such as the sleep fan—emit only one sleep noise. This works if you like the noise, but it can limit options.
However, Real Simple points out, some sound machines, such as the LectroFan from ASTI ($47; amazon.com), offer many different sounds. In creating the sounds, Nicolino says, he and his team extended white, pink, and brown noise to create several different noises, ranging from white noise to a very deep brown noise. This sound machine is, in effect, a white noise machine, a pink noise machine, and a brown noise machine all in one—great for someone who can’t stand staticky white noise or who wants different sounds for different situations.
Beyond the noise itself, you should consider whether the sound machine or app you’re looking at loops. Some—especially those that feature nature recordings—loop the sound, which can disrupt sleep, the magazine advises.
At the end of the day (or night, in this case), it all comes down to personal preference. “People are going to choose a sound simply on what they like,” Dr. Pelayo says. “Once people settle into a sound spectrum that they like, they stick to it.”
Research contact: @RealSimple