I’ve always been a light sleeper. A creaking floorboard sends me shooting out of bed. And don’t get me started on my neighbors’ late-night music fests.

I can’t sleep without something to drown out sounds: white noise.

A survey published last year by the American Academy of Sleep Medicine found over a third of Americans always or often experience sleep disruptions because of outside noise. To help, 18% of Americans use white-noise machines or apps, while nearly half use a fan at night.

My sleep saviors are a sound machine for my bedroom and sleep earbuds that pipe white noise to my ears when I travel. I think their effectiveness is indisputable, though the scientific community is still debating the value of white noise—particularly when it comes to long-term use and its effect on kids.

Here’s the tech that can help you sleep.

What the science says

Our ears don’t stop working while we sleep. The brain filters noise, allowing important sounds—like fire alarms—to wake us up. Many of us are more sensitive, and every radiator click or car honk puts us on high alert. Is white noise the answer?

“Obviously so many people are using it, so there must be something about it,” says Dr. Mathias Basner, a professor of psychiatry at the University of Pennsylvania’s Perelman School of Medicine who co-wrote a 2020 report on existing white-noise research. “The widespread use warrants further investigation.”

Some papers Basner and his colleagues evaluated found white noise can actually hurt sleep by disrupting sleep cycles, at least initially. It also might mask important sounds (like a baby crying) or cause hearing loss. “We basically concluded you can’t conclude anything,” Basner says.

Other research has shown a clearer upside. A paper published in 2021 in the journal Sleep Medicine found people in the bustling New York area fell asleep faster and awoke less often when playing white noise. Some of those sleep improvements continued for at least a week after the white noise stopped, says co-author Dr. Ana C. Krieger, director of the Center for Sleep Medicine at Weill Cornell Medicine in New York.

“We believe that white noise can be very beneficial to patients,” Krieger says. “But more research is needed.”

As to why it appears to work raises lingering research questions: Does white noise confuse the brain, reducing the impact of loud noises? Does it mask sounds that would wake people up? Does it calm racing brains, or signal the bedtime wind-down, lulling the brain to sleep?

Nap apps

If you’re looking for occasional white noise—like when your sick partner is snoring—try a phone app.

Three popular iPhone options, according to market-intelligence firm Sensor Tower, are White Noise Lite, White Noise Deep Sleep Sounds and Bedtime Fan: White Noise Baby.

Opt for an app that has a varied sound library. “White noise” is typically shorthand for a variety of background sound frequencies. Pink noise sounds like gentle rain. Brown noise is similar to an airplane hum. True white noise resembles static.

Be aware that apps tend to rely on short recordings that loop. You might not initially notice a pattern, but once you hear it, it can keep you awake—like a ticking clock.

Nightstand noise

Sound machines are a nice step-up. My colleagues swear by the $50 Dohm Sound Machine from Yogasleep (formerly Marpac). Its sound is created by a small fan blade, and can be adjusted by twisting the dome.

My favorite is the $50 LectroFan Classic . It’s digital, but uses mathematical models instead of recordings to create 10 electric fan sounds and 10 color noises, so there’s no annoying loop.

“Every time you listen to it, it’s slightly different,” says Sam Nicolino, chief executive of LectroFan’s maker, Adaptive Sound Technologies.

The company also has a $40 portable model, the LectroFan Micro2 , with a built-in battery. It’s roughly half the size of a Coke can but produces powerful sounds.

In-ear options

The portable LectroFan keeps my husband happy during travels, but I still turn to something more personal for my trips: sleep earbuds.

I know, falling asleep wearing AirPods or other earbuds can be painful. But these are different. When Bose discontinued its Sleepbuds , I panicked at the thought of traveling without them. So I was happy when former Bose employees bought the technology and introduced the $299 Ozlo Sleepbuds .

They have 10 flavors of white noise, with plans for more than 100, says CEO Rockwell Shah. The batteries last 10 hours, and they can stream audio from your phone. If you’re playing music, the Sleepbuds can detect when you fall asleep—based on respiration, movement and more—and automatically switch to your chosen sound. You can try them by renting them for $22 a month.

Anker offers similar earbuds for a smaller price tag, the $150 Soundcore Sleep A20 . One fun app perk: You can combine different sounds—such as brown and pink—to build your perfect mix.

Pump down the volume

If using it nightly, consider setting your app or device’s timer to shut off automatically during sleep, giving your ears a rest. And researchers urge caution if playing white noise for children, because their brains are still developing.

A study published last year in Sleep Medicine found that white-noise machines can be loud—over 91 decibels, which the National Institute for Occupational Safety and Health says is only safe for two hours.

Ideally, you should keep any persistent noise under 80 decibels, says Dr. Marlan Hansen, an ear surgeon, professor and head of the otolaryngology-head and neck surgery department at the University of Iowa.

If your TV is at a normal volume and you can still hear it above the white noise, that’s the right level, he says. If your white noise can drown out a chain saw, he adds, that’s just “exacerbating the problem.”

Write to Shara Tibken at shara.tibken@wsj.com