When it comes to settling fussy babies and helping them sleep, white noise is pretty magical. Research has shown that white noise can help 80% of infants fall asleep in just 5 minutes. Plus, the soothing sound significantly decreases the duration of crying and increases sleep in colicky babies, according to research in the Journal of Clinical Nursing. The icing on the cake: The American Academy of Pediatrics even recommends white noise to help improve Baby sleep. This, of course, is why white noise (aka shushing) is an essential element of the incredibly helpful 5 S’s for soothing little ones. White noise helps turn on your baby’s innate calming reflex, or their built-in “reset button” to calm crying and bring on sleep. But…what is white noise? Will you know it when you hear it? To be sure, here’s an easy white-noise cheat sheet to help you land on the perfect sounds to get your baby to sleep.

What is white noise?

White Noise Defined

White light is an equal mix of every color (i.e., all the frequency of light) and white noise is the sum total of all the frequencies the human ear can distinguish mashed together at the exact same intensity. While you’d think that would cause a headache-inducing racket, it instead results in a sound very much like the wind, or ocean, or the static that an untuned radio.

Benefits of White Noise for Sleeping and Bedtime Routines

The consistent staticky din of white noise creates a blanket of sound that not only masks other sounds…which can help babies, toddlers, everyone, fall asleep and stay asleep. (It can even distract infants, so they pay less attention to mild internal discomforts, like some teething or mild hunger, further bolstering ZZZs.) Note: They don’t hear the heartbeat; the heart is too far away. They probably hear the blood flow through the little arteries in the placenta, right by their heads. 

Think about it like this: When two people are talking at once, you can usually distinguish one voice and tune into what that person is saying. Now imagine everyone in the world talking at once. Your brain simply can’t pick out each voice…they blur together. White noise is like so many voices at once that other sounds—like a passing truck or a loud television—just disappear.

White Noise vs Pink Noise 

Essentially, pink noise is a “cousin” to white noise. It also contains all the frequencies that we can hear…but the rumbly sounds are dialed a little louder and the high pitched, squeaking, tinny frequencies are dialed down. While there are some promising studies on pink noise (it’s been found to help treat tinnitus, or ringing in the ears), right now, white noise is still the go-to for better sleep.

White Noise vs. Brown Noise

In brown noise the rumbles are dialed up even more and the high pitch ones dramatically lessened. Some examples of pink noise include the sound of rustling leaves and loud shushing and brown noise is the rumble of a car engine and low shushing.

What are examples of white noise?

People tend to be a little fast and loose with the term “white noise machine,” but many of the bazillion white noise machines and apps feature sounds that aren’t white noise at all. White noise is not chirping birds, or crashing waves, or whale songs, or lullabies. White noise is a steady mix of rhythmic or continuous shushy sound. And the best white white noise to help babies sleep mimics the loud rumbly sounds they heard in the womb. Here are some examples of white noise that work best to help sleep:

• Radio or television static

• Vacuum

• Whirring fan

• Hum of an air conditioner

• Strong hair dryer

• Steady running water

• Shushing

• Steady rain

What’s the best volume for white noise?

The best volume for white noise depends if your baby is upset or not. If your little one is calm, tune your white noise machine to fall between about 57 decibels (the level of a whisper) and about 68 decibels (the level of singing a lullaby). But if your baby is crying, white noise needs to nearly match their volume in order to turn on their calming reflex. While a baby's cry can top out at about 100 to 120 decibels, adjusting your white noise to fall just under 85 decibels should do the trick.

While the decibel scale can be a little confusing, SNOO is not! SNOO is the only white noise device specifically designed to give your baby the exact level of sound they need, at the exact time they need it. SNOO quietly shushes all night between roughly 57 and 68 decibels, and when your baby cries, the sound increases no more than roughly 85 decibels for just a few minutes.

Fun fact: SNOO isn't the only "smart" white noise machine! SNOObear’s white noise turns off after 30 or 60 minutes—your choice—and turns back on again if it "hears" your little one fuss.

Is white noise played through the phone effective?

It can be…if you’re using the right white noise sounds, like our pediatrician-designed SNOO sounds download. But keep in mind that phones release microwave radiation, so you need to put your phone on airplane mode if you place it near your baby. At the same time, white noise through a phone speaker sounds more hissy, which can sometimes be irritating to the listener. When a portable white noise machine is needed, consider SNOObie, which features the same effective white noise sounds babies love in SNOO, plus a few extras. And if you want something even more cuddly, SNOObear will be your baby's first friend.

How do I use white noise to help Baby sleep?

To start, simply play white noise in the background 30 to 60 minutes before your baby’s bedtime routine. After a short while, white noise will start to signal to Baby that their sleepytime is just moments away. This continues to work beautifully even after your baby’s calming reflex slowly disappears by 3 to 4 months. By then, the “white noise means sleep” association has been made, so, every time your baby hears the telltale white noise, they think, “I know that sound…that means it’s time to have good sleep.” Like magic!

For more on white noise advice, check out:

• Why Does White Noise Calm Babies?
• Common White Noise Mistakes to Avoid
• Newborn Baby White Noise Benefits
• White Noise and Transitioning to the Crib

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.