White noise is known to be a helpful way of masking other sounds. But can replacing one type of noise with another actually help you sleep?
The scientific evidence suggests that white noise can indeed help you sleep better. However, there are some concerns regarding young children listening to white noise too loudly and too often.
In this article, I’ll be looking at five research studies that have shown how white noise can help both adults and children sleep.
I’ll also discuss what sound machine manufacturers and sleep experts have to say about white noise, and how to use it safely.
Listen while you read
Here’s a recording of white noise for you to listen to. Does it help block out any other noise where you are? Do you find it easier or harder to concentrate on the article?
There have been several interesting studies investigating the potential for white noise to help people sleep better.
They tend to focus on specific groups, such as newborns and adults in noisy hospital environments. Still, the results are usually very positive.
1. Adult patients in a critical care unit
In 2016, researchers in Iran undertook a study to see if white noise would help patients in a critical care unit sleep better.
They split patients into 2 groups, playing white noise of 50-60 dB to one group, while the other group would have the normal sounds of the hospital ward.
They found no difference in reported sleep quality between the groups when they were admitted. But after 3 days, the group listening to white noise reported significantly better sleep than the control group. They concluded:
Sleep disorders are more common among patients in intensive care units. Environmental factors like noise is a common cause of sleep disorders. Based on the findings of this study, the use of white noise is recommended as a method for masking environmental noises, sleep induction, improving sleep, and maintaining sleep in the coronary care unit.
2. Adult patients recovering from heart surgery
In a similar study in 1992, a researcher at Huntsville hospital in Alabama looked at the effects of white noise on the sleep of patients recovering from heart surgery.
In this study, 30 patients were played ocean sounds through a white noise machine, while 30 would just have the normal sounds of the ward.
They found no difference in the time it took to fall asleep. However, the group listening to white noise reportedly had better overall sleep. This was based on better results for ‘sleep depth, awakening, return to sleep, quality of sleep, and total sleep scores’.
The author concluded that:
The use of ocean sounds is a viable intervention to foster optimal sleep patterns in postoperative CABG patients after transfer from the ICU.
3. White noise reduces the effect of changing noise levels in an intensive care unit
In a study in 2004, researchers looked at whether it was the volume of environmental noises or changes in noise volume that disrupted sleep more in an intensive care unit. And also if white noise would help reduce this disruption.
Interestingly, they used Polysomnography – the gold standard of sleep monitoring – rather than subjective or observational measures of sleep.
They found that white noise helped by reducing the difference between the normal background noise and louder noise:
Peak noise was not the main determinant of sleep disruption from ICU noise. Mixed frequency white noise increases arousal thresholds in normal individuals exposed to recorded ICU noise by reducing the difference between background noise and peak noise.
This is a particularly useful study, as it supports one of the main claims made about white noise – that it helps prevent sudden external sounds from waking people up.
Perhaps the most famous study of white noise and newborns took place in 1990.
In the study, researchers at Queen Charlotte’s Hospital in London looked at the effects of white noise on newborns between 2 and 7 days old.
They split the newborns into 2 groups of 20. One group was observed in silence in their cot to see how long it took them to fall asleep.
The other group was played white noise through a standard white noise machine (placed next to the cot, 30 cm from the head).
They found that 16 (80%) fell asleep within 5 minutes when listening to white noise. In contrast, 5 (25%) fell asleep in that time without white noise.
In addition, they made two interesting observations. Firstly, lower frequency noise worked better, similar to the frequency of a vacuum cleaner.
And secondly, that white noise didn’t help them settle if they were hungry, but did once they’d been fed.
5. Safety concerns when using white noise for newborns
This study didn’t look at the effectiveness of white noise, but I think it’s useful to go off on a brief tangent to look at the safety advice arising from it.
In 2014, a study by researchers at the University of Toronto made headlines around the world.
They tested a range of white noise machines, finding several that have a maximum possible volume that could be damaging to a child’s hearing.
However, the point being made by the researchers was that manufacturers should be clearer about how to use white noise – not that white noise is a bad tool for parents to use per se.
ISMs (Infant Sleep Machines) are capable of producing output sound pressure levels that may be damaging to infant hearing and auditory development. We outline recommendations for safer operation of these machines.
Recommendations for the safe use of white noise
As well as recommending that manufacturers reduce the maximum output, print safety warnings, and include auto-off timers, they had these helpful suggestions for parents:
1. Place the ISM as far away as possible from the infant and never in the crib or on a crib rail.
2. Play the ISM at a low volume.
3. Operate the ISM for a short duration of time.
What these few studies show then is that there is scientific evidence that white noise can help some adults and newborns sleep.
However, if you use it to help children sleep, it’s important to do so in a safe way. Don’t play white noise at an excessive volume or for extended periods of time, and avoid becoming dependent on it to help them sleep.
What do sleep experts say?
The National Sleep Foundation say that noise at night can wake you briefly, especially during the lighter sleep stages. So they suggest that white noise can help ‘mask activity from inside and outside the house’.
They also report that in their large sleep survey in 2012, 74% of Americans rated a quiet bedroom as being important for sleep.
Writing on her website Babysleepro.com, Dr. Rebecca Kempton, M.D., who is a pediatric sleep specialist, recommends white noise to parents.
She believes that babies are used to loud noise in the womb. She says that ‘the whooshing sounds they were exposed to in the womb are almost as loud as a lawnmower’. So white noise can be more comforting than silence.
What do manufacturers say?
As you’d expect, the companies that make white noise machines all speak highly of the potential for white noise to improve sleep.
On the Lectrofan website, there’s an explanation that reflects research study 3 above:
When a noise wakes you up in the night, it’s not the noise itself that wakes you up, per se, but the sudden change or inconsistencies in noise that jar you. White noise creates a masking effect, blocking out those sudden changes that frustrate light sleepers, or people trying to fall asleep.
They also explain why it can be helpful for babies. They point to the ‘shushing’ sound that parents naturally make to calm their babies, explaining that it’s simply white noise you make yourself.
They therefore suggest that white noise is a way of ‘outsourcing’ your shushing sound!
Lectrofan also believes that white noise creates a safe environment by blocking out sound that can be overstimulating.
It also reduces the number of sudden disturbances from siblings, TVs and music. And that it can help babies stay asleep longer by extending how long it is before they experience natural arousals.
Marpac say on their website that white noise can help if snoring keeps you awake, or if you live in a loud environment.
They suggest that it provides a ‘consistent sound environment that is especially soothing to infants, but also for adults’.
They also propose the interesting idea that parents can continue normal activities without tiptoeing around the house.
My personal experience
I have to admit that I tend to sleep best when I have absolute silence. My solution is usually to use earplugs and shut the world out as much as possible.
However, earplugs don’t always do the trick – they can only reduce so much noise. So on occasion, I’ve played pink noise (I find the lower frequency more relaxing), as I find it does a great job of blocking out noise.
But I have to play it on as low a volume as possible, so as not to find it more disturbing than the original noise. And recently, I’ve discovered that white noise in the form of natural sounds, like rain and waves, also helps me relax and fall asleep.
So for me, there’s a process I go through. First, I try to sleep naturally. If there’s noise keeping me awake, I reach for my earplugs.
But if there’s still noise getting through, and it’s driving me mad, I’ll probably read for a while, then try again.
Finally, if I still can’t sleep, I might finally try white noise or even music. But it’s not something I do every night, and would prefer not to, as I’d like to be able to sleep as naturally as possible.
So for me, even though I know it helps mask noise, it’s not my first choice method to try and sleep; it’s more of a backup option.
Do you listen to white noise at night, or play it to your child to help them sleep? Do you find it helps? Let me know in the comments below!