White Noise Machines

What a white noise machine does

A white noise machine plays a steady, even sound all night. White noise is a hiss, like static or a fan, and most machines offer other sounds too: deeper noise, a fan, rain, waves.

The idea is masking, not silence. A quiet room makes every small sound stand out: a car door, a neighbor's footsteps, a pipe. A steady sound raises the floor, so those changes are less sudden. The CDC's list of sleep habits asks for a quiet bedroom. When you can't get quiet, steady is the next option.

The radiator knock

The duplex radiator knocks around 2 a.m. every winter. I can hear it from across the alley. Margo says it's "the building saying good night". I say the building could use a quieter goodnight.

That knock is the perfect example of what a white noise machine is for. It's not loud, exactly. It's sudden. You're asleep in a quiet room, and then the room isn't quiet. Steady sound doesn't stop the knock, but it means the knock arrives into something instead of into nothing. Margo has never needed one. She sleeps through the radiator, the thermostat negotiations and, once, a snowplow.

How to read the white noise machine table

Every field shows only when the maker or the Amazon listing states it. A dash means it isn't in writing.

Sound source: real fan or digital

This is the main split.

• Real fan (mechanical). A small fan spins inside a housing and makes the sound itself. Nothing is recorded, so nothing loops. You change the tone by twisting the housing or switching speeds.
• Digital, non-looping. A speaker plays sound generated so it doesn't audibly repeat, as the maker states.
• Digital, looping or not stated. A speaker plays a recorded or generated track. Some loop, and a few people notice the seam.

We mark a machine as a real fan only when the maker says fan-based. A machine that plays a recorded fan sound is digital.

Number of sounds

The count of sounds as the maker states it. Some digital machines offer many; a fan machine may offer one sound with a range of tones and speeds, which isn't a count. More sounds isn't better if you only use one. Most people settle on a single favorite within a week.

Noise colors

White, pink or brown noise, as listed. White noise is the brightest, a hiss. Pink is softer. Brown is the deepest, closer to a low rumble or heavy rain. The brown noise machines page keeps only machines that list brown noise.

Sleep timer

Yes when the maker states a timer. A timer turns the sound off after a set time, for people who like sound to fall asleep but not all night. If you want it on until morning, check that it can also run continuously.

Power and battery life

• AC / plug-in. For the nightstand or dresser.
• USB. Can run from a charger or a laptop.
• Battery or rechargeable. For travel, with battery life in hours only when the maker states it.
• Battery backup. Keeps playing during a power cut, if the maker says so.

The portable white noise machines page keeps only the battery and rechargeable kind.

Dimensions

The machine's size, as the maker states it. Useful for a small nightstand or a travel bag.

Maker wording: health and nursery

Some listings use health words, or describe the machine for a nursery. We show that wording exactly as the maker states it, in its own column. We don't repeat it as a claim, and we don't add advice about a baby's sleep. This page is about adult use.

White, pink or brown: choose by the noise you're covering

There's no rule here, only a pattern worth trying.

• High, sharp sounds (voices, dishes, a TV through the wall): white noise covers the upper range well.
• Low sounds (traffic, a furnace, a radiator, a neighbor's bass): brown noise has more low end to match.
• Somewhere in between, or you find white noise harsh: pink noise is the middle ground.
• You like something that sounds like a room: a real fan machine.

If a machine offers several colors, try each for a few nights before deciding. The first night of any new sound is the strangest.

Volume and placement

My one opinion on these machines: a white noise machine is for steady sound, not loud sound. The reason is a hearing number, not a taste. The NIDCD, part of the NIH, says sounds at or below 70 dBA are unlikely to cause hearing loss even after long exposure, and that long or repeated exposure at or above 85 dBA can. It lists normal conversation at about 60 to 70 dBA. A sound machine runs for hours, beside you, every night. That's long exposure.

Few listings state a decibel figure. So:

• Set it lower than you think. If you'd have to raise your voice to talk over it, it's too loud.
• Put it across the room, not on the pillow and not right by your head.
• Don't turn it up to beat a loud noise. If the noise outside is louder than a comfortable machine, ear plugs are the better tool.
• Point it toward the noise. Between the bed and the door or window often works better than beside the bed.

Most machines plug in near the bed, so the cord matters too. Run it down the back of the nightstand or along the wall, away from the mattress and pillows, and place the machine where the maker's manual says.

Choose a white noise machine by room and use

• Bedroom, every night. Plug-in power, a sound you like, volume control that goes low, and a timer that can also stay on.
• Shared bedroom. A machine placed between the bed and the noise, at a level both sleepers accept. Compromise is part of the volume knob.
• Home office or apartment wall. A fan or brown noise machine can soften voices through a shared wall during the day too.
• Travel. Small, battery or USB, with stated battery life. See portable white noise machines.
• Light sleepers in old houses. A deeper sound for pipes and radiators, and placement toward the source.

Night-shift note: I spent seven years producing sound for people's ears at 3 a.m. The best compliment a listener ever gave me was that they didn't notice the music changing. That's the job description of a good white noise machine.

A white noise machine vs a box fan

Plenty of people sleep with a box fan running for the sound. It works on the same idea. The differences are practical.

• Air. A box fan moves air across the room. In a Minnesota January, that's a cold breeze nobody asked for. A sound machine makes sound without the draft, or with only a little air inside its housing.
• Size. A fan takes floor space. A sound machine fits on a nightstand.
• Control. A fan has a few speeds. A machine usually has finer volume steps, a timer and a choice of tones.
• Noise you don't want. An old fan can rattle or click. That's the kind of sudden sound you were trying to cover.

Margo keeps the duplex at 66°F all winter, and a running fan in January would be treated as a declaration of war. Dev's upstairs office uses a sound machine instead. (He has opinions about the 66. They have not been adopted.)

Features beyond the sound

The sound fields come first, but a few other details decide whether you'll like the machine at 2 a.m. Check the listing for:

• Lights. Some machines have a night light, a glowing display or a lit button. If you want a dark room, make sure it can be turned off.
• Memory. Whether the machine remembers your last sound and volume after a power cut or when you unplug it.
• Fade. Some timers fade the sound out gradually instead of stopping it.
• Controls. Buttons you can find in the dark, or a lock so you don't change the sound when you reach for your glass of water.

None of these are in our table unless the maker states them, and none matter more than the sound itself. They're the tiebreakers.

Care and setup

• Dust the vents. Fan machines pull air through the housing; a soft brush keeps them clean.
• Keep it dry and off the floor if you mop.
• Check the cord now and then for wear, and replace the adapter only with the one the maker specifies.
• Clear the settings of features you don't use, like lights. Some machines have a night light or display; check whether it can be turned off if you want a dark room.

Who should skip a white noise machine

• Your bedroom is quiet and nothing wakes you. Enjoy it.
• You dislike any sound at night. Ear plugs or sleep ear muffs reduce sound instead of adding it.
• The noise is very loud. A machine shouldn't be turned up to compete. Plugs, or fixing the source, work better.
• You just want to try the idea. A free app on a phone across the room is a fine test before you buy anything.

Related pages

• Sleep accessories, the section page
• Brown noise machines and portable white noise machines
• Ear plugs for sleeping, the other answer to noise
• Sleep sanctuary guide, for light, sound and temperature in one room
• Best white noise machines, ranked by a written rule