After 20 hours of research and testing, including interviews with one sleep researcher, two audiologists, and a sound engineer, we’re confident the LectroFan by ASTI is the white noise machine you’ll want to fall asleep with.
Thanks to its electronically generated, nonrepeating white noise options—which sound a bit like soft static—it worked as well as or better than the five other tested machines at masking squalling cats, barking dogs, and snoring roommates. Its simple controls are easy to use (even in the dark), its range of volume is wider than that of other devices we tested, and its small size is convenient for travel and won’t dominate your nightstand.
If you prefer an old-fashioned, low-tech machine that produces more subtle noises, the Marpac Dohm DS is a good option. Whereas the LectroFan sounds a bit like a loud “shhh” or static, the Dohm DS generates noises that are more like what you hear when holding a seashell or a cupped hand over your ear. This model is the original white noise machine, and its design has remained virtually unchanged since 1962. It costs about the same as the LectroFan currently, but it has a bulkier shape and is a little harder to operate and adjust. On top of that, in our tests it didn’t perform quite as well at masking noise.
If you need a white noise machine only occasionally, such as when you travel, you may be satisfied with a smartphone app. For iPhone, we love the free myNoise app, which offers a customizable medley of white noise tones. While the other iPhone apps we tested offer limited sound options, myNoise’s clever interface lets you adjust specific frequencies to create your own blend of white noise. For Android, we like Noisli. It isn’t quite as good as myNoise (which is available only in beta for Android), but it does allows you to layer white noise frequencies, and it’s easier to use than other Android apps we tried. Both apps sound similar to the LectroFan, just with fewer frequency options. The sound quality for both will depend on your phone’s speakers.
To learn what features to look for in a white noise machine for sleep, I spoke at length with Michael Perlis, PhD, director of the behavioral sleep medicine program at the University of Pennsylvania School of Medicine, who is currently working on a study of the use of white noise machines in treating insomnia. I also emailed with Stéphane Pigeon, PhD, a sound engineer who specializes in white noise; Pigeon is also the creator of myNoise, our favorite white noise app for iPhone. (I originally reached out to him because I was curious about his app. We ended up selecting his app after testing four.)
To learn about using white noise machines with infants, I spoke with Lisa L. Hunter, PhD, scientific director of research in the audiology division at Cincinnati Children’s Hospital, and I corresponded by email with Andrew Dimitrijevic, PhD, director of cochlear implant research at Sunnybrook Health Sciences Centre in Toronto.
I’m the research editor for The Wirecutter and The Sweethome, assisting our writers and editors with product research and reporting for more than 100 guides to date, including many of our audio-gear guides.
If your bedroom isn’t as quiet as it could be, and you think the noise is affecting your sleep, you may want to try a white noise machine. Medical studies have shown that white noise machines can help people stay asleep in noisy environments such as an ICU, and some sleep researchers suggest them to patients who find ambient noise at night bothersome.
If you already use a sleep machine with prerecorded sounds such as waves or rain, consider one of our picks, which produce random, constant white noise. Such invariant white noise is better at blocking sounds and is less likely to itself disturb your sleep.
If your sleep quality has changed suddenly and you’re not sure why, don’t immediately run out to buy a white noise machine. “Sleep is likely a very sensitive barometer of your health status,” U Penn’s Michael Perlis told me. Unless you know for certain that environmental noise is the culprit (a new neighbor started blasting music at 2 a.m., your partner started snoring, or the like), it’s best to talk with your doctor first.
The best type of white noise machines for sleep create “meaningless, nonrepetitive sounds, complex frequencies, and invariant volume,” said Perlis. This type of noise is the most likely to block disturbing noises while not itself creating meaningful sounds that could wake you.
White noise machines fight noise with noise, sound engineer Stéphane Pigeon explained to me in an email. They produce low-volume, constant, random, meaningless sound across all audible frequencies, from very low (20 Hz) to very high (20,000 Hz). The white noise basically creates a wall of sound defense, protecting you from intruding noises that could engage your brain during sleep.
Many sound machines marketed for sleep offer recordings of birdsong, rainfall, crashing waves, or other natural sounds, but Perlis said this type of sound could actually disturb your sleep. Even sudden noise that doesn’t jolt you awake can still cause “microarousals” in your brain. “This can make your sleep less nutritious and more shallow, even if you don’t perceive it,” Perlis told me. You want noise that is as meaningless—and, frankly, boring—as possible. For that reason, we stuck to machines whose primary sound offering was random white noise.
A white noise machine will likely sit on your nightstand next to your bed, so we eliminated machines that were notably large or ran only on batteries. We also avoided machines that had bright digital displays, clocks, or lights that could compromise the darkness of the bedroom.
We then looked at reviews of white noise machines on Sleep Like The Dead and Amazon, focusing on the best-rated machines that met our criteria. We concentrated on white noise machines for use by adults, and we didn’t test any of the machines mentioned in this guide with babies or young children. The use of white noise at high volumes with babies is the subject of some concern, which we cover below.
We narrowed our list of nine white noise machines down to six that I decided to test: the Marpac Dohm DS, the Marpac Rohm and Hushh (two models that are virtually identical aside from some features in the latter for use with babies), the ASTI LectroFan, the Homedics Deep Sleep II, and the Sleep Easy Sound Conditioner.
To test the machines, we ran through their features and judged how easy they were to use. We then used a sound-level meter to measure the decibel range of each machine, from quietest to loudest. We measured the sound levels 18 inches away from each machine, simulating the distance between someone lying in bed and the machine sitting on a nightstand.
In our measurements, all the machines remained under 85 decibels (dBa) at their max setting. According to the World Health Organization, 85 decibels—which is about as loud as a blender—is the maximum volume threshold (PDF) for eight-hour exposure without the risk of long-term hearing damage. We wanted a machine that allowed precise volume control over a wide range of sound levels, particularly at the low end.
Next we set up recordings of common nighttime nuisances: barking dogs, fighting cats, and snoring. With the recordings playing in an adjacent room behind a closed door, we sat 18 inches behind the sound machine. Starting at the lowest volume setting, we slowly increased the loudness for the machine until we could no longer perceive the intruding noise, noting the decibel level required to block the sound.
To be honest, all the machines we tried sounded more or less alike (except the Dohm DS, which had a more complex, layered sound). The LectroFan didn’t sound better than the other machines, but it was just as capable or slightly better at masking sound during our noise tests. It generates white noise electronically using algorithms, so the sounds it produces are truly random and won’t repeat, something that Michael Perlis, director of the behavioral sleep medicine program at the University of Pennsylvania School of Medicine, told me is a good feature of a white noise machine for sleep. The LectroFan’s 10 white noise settings, ranging from “dark noise” (low frequency) to “white noise” (high frequency), sounded like variations of low rumbles, rushing wind, or static—neither pleasant nor unpleasant, and definitely random and meaningless.
According to our sound-level tests, the LectroFan’s 30 volume settings ranged from a whisper-quiet 31 dBa to a thoroughly loud 80 dBa (about as loud as a garbage disposal). All the machines we tested measured under 85 dBa at their max setting (when we measured sound from 18 inches away). A machine that allows for fine volume control, like the LectroFan, can be at its lowest possible setting yet still block noise. By comparison, some of the other machines we tried had a narrower volume range that we found more difficult to adjust. To be clear, we didn’t notice a huge variation in the sound-blocking performance among the machines, and they were typically within a few decibels of one another for the minimum volume required to mask the offending noise.
Measuring just 4 inches in diameter and 2 inches high, the LectroFan is the second-smallest machine in our test group. It takes up little room on a nightstand, and it’s small enough to go into your luggage for travel. (It conveniently uses a USB cord and wall-power adapter, which you could swap for your USB wall charger to save more space when you’re packing.)
With its minimalist, three-button interface, we found changing noise settings and volume on the LectroFan easier than on the other white noise machines, which had more-complicated controls. The LectroFan was the only white noise machine we tested that was easy to adjust or turn off in the dark, without our needing to see or pick up the device. This model also has a 60-minute timer, a useful feature if you want to set the machine to run as you fall asleep and then turn off.
The LectroFan features 10 “fan sounds,” including “box fan,” “attic fan,” and “industrial fan.” Unless you particularly like fan sounds, we’re not sure why you would need or use these settings, so we ignored them, since the white noise settings worked better at masking sounds.
We’re not the only ones who like it: The LectroFan currently has an average rating of 4.7 out of five on Amazon, across more than 4,500 reviews.
Since the LectroFan is so small, we wish it had a built-in battery, which would be helpful for travel or if you don’t have an outlet nearby.
The Marpac Dohm, which the company touts as the original white noise machine, has had a devoted following for more than 50 years. Relying on a fan to make noise, the Dohm DS (the two-speed version) produces a slightly more pleasant sound than the LectroFan, something akin to what you hear when you hold a shell over your ear, or to the sound of wind rushing through a field. In contrast, the LectroFan and other electronic white noise machines produce sound that is more like a soft static or “shhh.” We found that the Dohm DS performed slightly poorer in our sound-masking tests than the white noise machines that generated noise electronically. We also noticed a slight whining undertone when running the Dohm DS on its high setting.
We do understand why the Dohm DS has a loyal following: There’s something innately appealing about its low-tech, no-frills, analog build. It has a single button that lets you switch between low, high, and off, and you can make subtle adjustments to the tone and volume of the noise by twisting the plastic housing, which opens or closes the cutouts.
While the simplicity of the Dohm DS’s design makes it a great choice if you want to keep your bedroom a tech-free haven, adjusting the volume and tone on the Dohm DS is a bit more difficult than on the LectroFan. The Dohm DS also has a narrower volume range than the other machines, so its lowest setting, at about 61 dBa measured 18 inches away, is louder than the softest setting on the other machines (our pick, the LectroFan, goes down to 31 dBa). On the higher end, it can reach only 69 dBa—other machines can run louder, but we doubt you’d want a white noise machine louder than that.
Still, the Dohm has had many thousands of satisfied owners over the years (including the author behind this approbation in The New York Times), and it boasts an overall 4.5-star rating with more than 9,000 reviews on Amazon. We also like that you can send your Dohm back to the factory in North Carolina for repairs.
White noise apps can come in handy for travel or if you need to mask sounds only occasionally. They are not a great choice for use every night, because the sound quality isn’t as good, they don’t offer as many white noise options, and you’ll need to fiddle with your smartphone each night. But when you need temporary assistance, using an app is better than listening to a white noise track—with those, the longest recordings generally last only 30 minutes, so they can have a disruptive restart (or stop altogether). We’ve found a few apps that produce true white noise, don’t have ads, and remain simple to use.
After testing four iPhone apps, we like myNoise (created by the sound engineer we spoke with, Stéphane Pigeon). The free app offers some interesting sound mixes, but you should first check out the “White Noise & Co” setting; its unique color-coded slider allows you to adjust white noise frequencies, from lowest to highest, to create a customized white noise mix. myNoise is also the only app we tested that offers an “animate” setting, which automatically varies the volume of the frequencies to create unique white noise blends. You can set a timer or alarm from within the app, too.
For Android, we’d go with Noisli, which a Twitter follower recommended to us. You can’t adjust color-coded frequencies as in myNoise (which is available only in beta for Android), but you can layer multiple white noise sounds and adjust their volumes to create a custom blend. The simple icon-based interface offers 12 nature sounds and four white noise options, and the app has a timer. Of the eight Android apps we tried, Noisli has the least-distracting and easiest-to-use interface.
The white noise from both apps sounded similar to that of the LectroFan, though with fewer frequency options. The volume and clarity of the apps will depend on the quality of your smartphone’s speakers, and pairing your phone with a Bluetooth speaker will produce better results.
We tested these machines at 18 inches from our ears, which is a valid location for a white noise machine, but that’s by no means the only correct placement within a room. I asked Marpac, maker of the Dohm, whether there is an optimal distance or placement for the machine during sleep. Liz Heinberg, a spokesperson for the company, replied, “Our overall recommendation is to experiment.”
She suggested trying to position the Dohm between where you sleep and the greatest source of noise. “Often this is a window facing the street, a doorway in a hotel room, or a thin wall,” Heinberg explained. “The placement is most important when the noise issues are more dramatic and more definitely coming from a particular source.”
A spokesperson for LectroFan manufacturer ASTI echoed that notion: “Distance or placement for sleep doesn’t really matter,” she said, as long as it’s within hearing distance.
In short, regardless of which machine you choose, you should experiment with different distances, based on the source of disruptive noise and other considerations (outlet availability, your bedroom layout), to find a location that lets you operate your white noise machine at the lowest possible effective volume.
Several popular infant sleep guides and some medical studies have suggested putting a white noise machine or some other sound machine in a baby’s room to help the child sleep better. But you may want to talk to your pediatrician before trying any, as well as to use caution, particularly with the volume.
“The level that some noise machines are capable of putting out is far too high” for infants’ ears, wrote Lisa L. Hunter, scientific director of research in the audiology division at Cincinnati Children’s Hospital, in an email. The American Academy of Pediatrics recommends (PDF) that newborns in neonatal intensive care units be exposed to sound levels no higher than 45 decibels to avoid potential hearing damage. Hunter cited a 2014 study (PDF) that tested decibel levels of 14 infant sound machines. The study found that all the machines the researchers tested were capable of producing sound in excess of 50 dBa, and several went up to 85 dBa (this is in line with the maximum decibel output of the machines we tested, as well.)
“The first thing parents should do is to turn the sound machine to a soft level, so that it doesn’t interfere with hearing soft conversation,” Hunter said. She also suggested choosing a machine with a timer setting in order to further limit how long the infant is exposed to the sound.
Hunter also raised a concern about the effects of exposing infants to “non-salient, non-meaningful sound” while they sleep. “We know almost nothing about the long-term impact of white noise on the baby’s ability to listen. But animal studies of newborn animals suggest that white noise may mask out sounds that are more specific (like speech and music), causing the brain to develop differently.” Hunter pointed to preliminary published findings from a study led by Andrew Dimitrijevic, director of cochlear implant research at Sunnybrook Health Sciences Centre in Toronto, which compared a small group of children who had used white noise machines as infants with those who had not. The study found that the brains of the children who had been exposed to white noise were less responsive to sound patterns typical of everyday conversation than the children who had not been exposed. That said, like many research findings related to infants, this data comes from a small group showing preliminary results—and no research yet shows whether this effect plays out in any measurable way in a child’s learning, speaking, or other forms of development.
The Homedics Deep Sleep II is the largest machine in our test group, measuring 9 inches tall and 8 inches wide. It commands a lot of space on a nightstand, and the blue-lit digital display (which you can dim) and the plethora of buttons on its face make it seem more gadgety than practical. It also comes with a number of superfluous nature, ocean, and “sleep therapy” sounds, which, as we note above, are not ideal for sleep. Its 11-button interface is complicated to use and was occasionally unresponsive in our tests.
The Sleep Easy Sound Conditioner, which features an internal fan and looks like a Dohm knockoff, was a total bust in our tests: It jittered and rattled uncontrollably when we switched it on. Amazon reviews indicate this is a common problem.
The Marpac Rohm, which blocked sound well in our tests, has 40 volume settings, allowing for precise adjustments. But it has just two white noise options (and a crashing-waves setting), and the controls are on the side of the machine, meaning you have to pick it up to make adjustments. We found the buttons a bit stiff, too. Although it’s designed as a travel device, it’s not much smaller than the LectroFan, which we think is already small enough for travel. If you need a white noise machine only for travel, you’ll probably be fine with a smartphone app.
We also looked at the Marpac Hushh, which is identical to the Rohm except for a few baby-specific features (a nightlight and a lock). We didn’t test it with babies.
The Homedics Deep Sleep I is a pared-down version of the Homedics Deep Sleep II, lacking the digital display and some other features. We didn’t test it, because at nearly 7 inches high and 5 inches wide, it’s still quite big.
(Photos by Michael Hession.)
We're gonna have to have a whistle-off!