White noise sounds similar to the static noise heard when there’s no signal on your television or radio. A sound you’d probably try to get rid of as quickly as possible.
So why is there a whole industry built around white noise production? And can it really help you relax, fall sleep or study better?
To understand why people would want to listen to it, let’s first take a look at exactly what white noise is.
What is white noise exactly?
It’s helpful to look at the name itself to start with. White noise gets its name from ‘white light’. In simple terms, white light is all colors, or frequencies of color, combined together.
In a similar way, white noise is a combination of all the different frequencies of sound the human ear can hear.
The white noise we talk about usually isn’t every possible sound put together though.
White noise is the signal, or frequency, created when all the different frequencies of audible sound that the human ear and brain can perceive are put together at a similar level.
The sound of white noise we hear as humans is the sound of all the frequencies between 20 and 20,000 Hz. So you’re literally hearing around 20,000 different tones of sound all at the same time.
If you think about it this way – imagine you’re sitting in a quiet restaurant. You’ll be able to pick out the individual voices of your companions, and perhaps those on nearby tables.
But now imagine you’re in a sports stadium waiting for the game to start. There could be thousands of people all talking at the same time, and it will sound like a blurred roar.
White noise has a similar effect. You hear so many different tones all at the same time, it blurs into that ‘hissing’ or ‘shushing’ sound.
It’s also why nature sounds, such as rain, wind, waterfalls or oceans, are often included on white noise players. There are so many different tones created by those forces of nature, that it turns into natural white noise.
What is pink noise?
The simple explanation is that pink noise is a variation of white noise which sounds deeper, and with less of a high pitched hiss.
The more complex explanation revolves around why white noise sounds high pitched in the first place.
The reason is that each octave contains twice as many frequencies as the one below it. So, for example, between 100 Hz and 200 Hz there are 100 distinct frequencies.
But between 200 and 400 Hz there are 200 frequencies. So by the time you get to 20,000 Hz, there are many more frequencies than there were at the lower end of the range.
When pink noise is created in a sound lab, the sound engineers will usually reduce the volume of each successive octave to compensate for the extra frequencies.
This balances the sound out by giving more energy to the lower octaves, and gives it a deeper sound overall than white noise.
What is brown noise?
Brown noise, sometimes called Brownian noise, sounds even deeper than pink noise, and considerably deeper than white noise. It often sounds like rushing water – like a waterfall.
It’s not named after the color brown, but after Robert Brown, who discovered Brownian motion. This is because the signal is produced by the random pattern of particle movements.
Brown noise can be produced, but not the same way as white noise or pink noise, and is much harder to create. Sound engineers have to use each sample to create the next one with an element of randomness introduced to the previous sample.
Can brown noise make you lose bowel control?
The legendary ‘brown note’ is supposedly an infra-sound frequency that makes people lose control. Despite being an amusing urban legend, brown noise shouldn’t make you lose control of your bowels though.
However, experiments have been done by scientists, the military and in documentaries showing that there is no ‘one frequency’ that works on all people.
Yes, some people may react badly to the resonance of certain frequencies, but there is no one sound you can create to make masses of people all run for the toilet.
What is white noise useful for?
Because white noise contains all audible frequencies, its most common use is to mask unwanted sounds.
Most people find that they easily get used to the noise and don’t find it disturbing. It literally fades into the background, and takes other external sounds with it.
So who might find it useful, and in which situations?
1. Helps you sleep by blocking out disturbing sounds
For light sleepers who are easily kept awake by external sounds, listening to white noise at night can help block out disturbing noise.
So if you have trouble falling asleep because of the sound of traffic or music, white noise can mask that annoying sound.
You need to have the white noise loud enough for this to work properly though. Otherwise it will help mask other sounds, but not hide them altogether.
The other theory behind why white noise helps you sleep is that your brain is incredibly active and loves stimulation. So any noise in the night will engage your brain.
Having a constant white noise will therefore satisfy your brain’s need for stimulation and prevent it from getting overexcited when it hears sudden noise in the night.
You can also experiment with different kinds of white noise. If the sound keeping you awake is a deep traffic noise, then maybe try pink or brown noise instead as they have more strength at the lower frequencies.
2. It helps babies to relax and sleep better
Babies are easily kept awake or woken up by sudden sounds. White noise can help to drown out these sounds and keep them sleeping for longer.
Babies are already accustomed to listening to constant noise – the womb isn’t a quiet place, and white noise is sometimes thought to imitate the sound of blood rushing in the womb.
3. Can help you concentrate – for a while
While writing this article, I’ve been listening to pink noise constantly. I can hear the sound of traffic quite loudly from where I work, but the pink noise completely drowns it out.
This stops me from being distracted by changes in the volume of traffic, loud motorbikes, trucks and beeping horns.
I find it’s very effective and I’m so used to the sound now that as soon as I put it on I feel focused, and it fades nicely into the background.
It’s also sometimes used by people who work in other kinds of noisy environments, such as manufacturing or where there’s a drone of technological devices.
However, despite my own positive experience with white noise, some studies have shown that listening to white noise constantly to aid concentration can have a negative impact on your performance, stress levels and memory.
Other studies have been done to see if white noise can improve the concentration of children with attention difficulties. It appears that it does in some situations, but also decreases the performance of children who don’t have attention problems.
Overall, it seems this is still a developing area. My personal experience is that listening to white noise is better than listening to the drone of traffic. But perhaps after a few more days or weeks, it will start to irritate me.
4. Helps mask tinnitus
I can also personally attest to the theory that white noise helps ease tinnitus. Having had chemotherapy for cancer treatment 2 years ago, I have tinnitus as a permanent side effect of the Cisplatin drug.
Especially bad at night time, or if I’m tired, ill or stressed, I find that white noise in any form – pure or sounds of nature – helps to block out the ringing I hear from tinnitus.
5. Promotes relaxation
Although pure white noise, like that heard on your television, isn’t usually thought of as relaxing, nature sounds often are.
Many people find the sound of oceans, rivers, forests, waterfalls and rain calming, relaxing and peaceful. It may not be for everyone, but most people will state that one of the joys of being in nature is listening to the sounds.
So the next time you’re feeling stressed, why not have a listen to the sound of an ocean or waterfall and see if it helps you unwind?
Where can you listen to white noise?
There are many different options for listening to white noise. Mobile phone Apps, online players that let you mix nature sounds, audio downloads, and household appliances even.
To find out more about these options, take a look at my suggestions for sources of free white noise.