Sounds Of Silence: The Best Noises For Sleep

Noise can help you sleep. Not just fall asleep but actually improve the quality of sleep.

You’ve probably heard of white noise, maybe even in relation to sleep, but there are many more “colored” noises out there.

In this post I’ll cover the best noises for sleep: if there is one that’s better than the rest and which one might best suit your needs.

Table of Contents

The different colors of noise explained

We could get very geeky and technical about these definitions, but then we would have to get even geekier about frequencies, octaves, and whatnot. Which I mostly prefer NOT to do (life is too short)!

So, let’s just boil it down to a barebones explanation that allows us more non-techies out here to discuss the concept of colored noise without frying our brains in the process.

You can try this article, if you’re interested in a more technical explanation of the exact differences between the different colored noises.

Colored noise – white noise, pink noise, brown noise, and blue noise – is basically a broadband noise that encompasses the entire frequency range of sound that’s perceptible to the human ear (between 20 to 20,000 hertz). (*)

HOWEVER, depending on how the output (energy) is distributed on the scale (higher or lower), the “color” of the noise will be different.

White noise

In white noise all the frequencies have the same intensity. Higher, mid, and lower frequencies register with the same strength to the human ear.

Pink Noise

In pink noise, the higher frequencies are buffered and the lower frequencies are louder, so it sounds softer than white noise.

Brown Noise

Brown noise, on the other hand, contains almost no high frequency sounds at all, so the lower frequencies are even more noticeable than in pink noise.

Blue Noise

Blue noise is the opposite of brown noise. Meaning there are pretty much no low frequencies at all, so the higher frequencies are very noticeable – it’s very high pitch.

White noise, pink noise, brown noise and blue noise are all considered masking sounds

That means that regardless of the frequencies they emphasize (the color), the fact that they produce constant sound across the entire range effectively helps our brain to NOT pick up other random sound in our environment.

They basically increase the stimulation threshold the environmental sound would have to overcome to be registered by the brain. (*)

When you’re woken up by a sound in the middle of the night, that’s your central nervous system reacting to a signal in your environment that you might need to pay attention to.

The louder the sound, the higher the chances it will wake you up, but even a soft sound can bring you out of sleep. It’s the inconsistencies (suddenness and randomness) of the sound patterns around you that do it, more so than the actual volume of the sound.

Masking sounds work, because they “occupy” the scope of our auditory system with an even, steady flow of sound, preventing other random and uneven sounds to register and wake us up. (*)

The best noises for sleep – good noises vs bad noises

So what are the best noises for sleep?

Sounds affect people in different ways, depending on the individual sensitivities of each person.
It also depends on things like decibels (how loud it is) and for how long one is exposed to the sound (whether or not it’s chronic). But even short-term exposure can cause damage, if it’s loud enough. (*)

Noises can be good for you or bad for you.

Stress

When we’re exposed to a sound that we perceive as stressful – because it’s too loud, because we find the pitch nerve-wracking, because it’s disturbing our concentration, our relaxation, or our sleep – our endocrine system will react.

We release stress hormones, such as adrenaline, norepinephrine and cortisol, which will affect our body and nervous system in many ways.
We’ll register it in our heart rate, our blood pressure, in our blood fat and sugar levels, and even in blood viscosity (thickening). All of these are risk factors for heart attacks, arteriosclerosis (blood thickening) and hypertension, among others. (*)

Noise is a completely recognized psycho-social stressor that affects our body physically, including our neurological (mental) state. (*)

Creativity

But noise or ambient sound has also been shown to enhance creativity, for instance.

Research shows that a moderate level of noise (approx. 70dB) increases creativity by promoting abstract processing.
On the other hand, this increased abstract processing comes at the cost of a higher difficulty in processing information. This means that level of noise is not the best if you want to focus on a task (like studying say).
Noises higher than 85 dB seem to impair both focus and creativity. (*)

Relaxation

Of course, certain sounds or noises can also promote relaxation and soothe anxiety.

Such is the case with the different types of white noise, pink noise, brown noise, but also even just plain music (you enjoy). (*)

The best noises for sleep – White Noise vs Pink Noise vs Brown Noise

Out of all the colored noises, the most effective colored noises for sleep according to science are white noise, pink noise, and brown noise.

But is there one that’s better than the others?

WHITE NOISE

Out of all the colored noises, white noise is the most studied, for no other reason other than the fact that “white noise” is the general term for all of these types of noises.

Meaning, pink noise, brown noise and blue noise are all a type of “white noise” – a broadband noise across the entire frequency audible to humans.

It includes all colors, let’s say (as white does). The effort to study the different types (colors) of broadband noise is much more recent.

So, white noise has more research behind it proving its beneficial effects on stress and sleep. (*)

Including improving the quality of sleep. (*)
It has also been shown to reduce sleep issues, like sleep interruptions and sleep latency (how long it takes you to fall asleep). (*)
It’s a classic for soothing colicky babies and increasing their sleep duration. (*)

It works!

What else is white noise good for?

Improving visual memory and helping to soothe tinnitus (*)
Enhancing verbal recall and lexical acquisition (learning and remembering new words) (*)
Enhancing the memory performance in kids with ADHD, although it seems to disrupt it in children without ADHD (keep in mind)! (*)
And it has also been shown to improve physical balance in young and older adults, interestingly enough (*)

Sources of white noise:

Good ol’ radio or television static (classic!)
Whirring fans, vacuum sounds, hair-dryer sounds, the humming of air conditioners

PINK NOISE

After white noise, pink noise is the most researched and although it doesn’t have as many papers behind it, when compared to white noise it actually seems to do a bit better for sleep. (*)

One of the explanations proposed is this might be because pink noise is the most common signal in biological and physical systems. (*)

So both humans and nature seem to run on mostly pink noise and therefore it would be the most “natural” for us.

In fact, an interesting theory on the different preferences people have to the different colored noises and the different sensitivities they have regarding ambient sounds, might be due to their own individual, natural level of background neural noise. (*) The noise level of the functioning of their own biological systems.

Pink noise has also been shown to synchronize with brain waves, lowering their complexity and increasing stable sleep duration. (*)
By amplifying Delta wavelengths in the brain, it promotes stage 3 sleep, aka. non-rapid eye movement (NREM) sleep, aka. deep sleep. This is the most restorative stage of sleep, so it improves sleep quality. (*)

What else is pink noise good for?

It improves memory (*)
And induces relaxation (slowing brain waves) (*)

Sources of pink noise:

Heartbeats
Steady soft rain
Wind rustling through trees
Gentle ocean waves

BROWN NOISE

There’s little research on brown noise specifically, but it has been shown to improve sleep quality, along with white and pink noise. (*)

What else is brown noise good for?

It has been shown to help concentration and focus in open office settings, where constant chatter and random noises are a common thing. Again, it provides a useful sound masking effect that allows you to focus on your task more effectively. (*)

Sources of brown noise:

Thunder or low roaring sounds
Strong waterfalls or waves crashing
Strong sounds of water moving in general (rivers, heavy rain, etc.)

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SHOULD YOU listen to white noise or colored noise frequently?

The research is not all roses on white noise. Although they’re excellent noises for sleep, there are human and animal studies on the potential damaging effects of too much white noise, both on infants and adults.

Mental processing

In animal studies, masking environmental sounds with white noise during the development stage or early life slowed processing acuity (mental processing sharpness and speed), although it did not seem to have the same effect on adults. (*)

It’s also been shown to reduce spatial sensitivity (the ability to perceive visual information across the spectrum), possibly by interfering with GABA receptors. (*)

Noise-induced hearing loss

In humans there is more of a concern about the negative effects white noise might have on the hearing system long-term.

Noise-induced hearing loss is not uncommon with high-level noise exposure, but even a moderate noise level can cause damage, if you’re exposed to it for long periods of time.

The levels considered acceptable for humans are usually 90dB for no more than 8 hours, 95dB for no more than 4 hours, and 100 dB for no more than 2 hours. (*)

This is especially the case for babies and children, who are still developing.

Infant sleep machines and Apps can produce noise levels over the safe limits, so it’s important to use them conservatively, keeping the machine at a lower volume setting, and not have the device too close to the child’s bed. (*) (*)

Neuroplasticity

But it may not be very good in general for adults long-term either.

There’s some research that suggests that due to the brain’s ability to rewire itself (neuroplasticity), regular white noise exposure might cause changes in the brain that degrade cognition (mental processing) in the long-term.

So, although white noise machines might produce good short-term relief, they might undermine the integrity of the brain and the auditory system further down the line. (*)

So what are the best colored noises for sleep (bottom line)?

In a nutshell, when we compare the colored noises for sleep, pink noises seem to do a bit better than white or brown noises, but all three have been proven to be effective in promoting sleep.

Either by helping you fall asleep faster, preventing sleep disruption caused by external sounds (sound masking), or even by promoting deeper stages of sleep.
White noise sounds harsher than pink sound, which seems to be more prevalent in nature and our own biological systems. And brown noise is the deepest of all broadband masking sounds. So depending on your natural preferences and sensitivities you might favor one over the other.

The best way to determine what are the best noises for sleep in your case, maybe start with a type of pink noise and see if it works for you.

If you find the sound too soft, try white noise. If you find the sounds are still too “high”, try some kind of brown noise, that’s deeper.

Either way, take into account that it might not be the best long-term solution to getting better sleep.

The best noises for sleep are basically the ones that make you feel more relaxed.

Do you have any personal experience with colored noises you might like to share? What’s your favorite for sleep? Let us know in the comments below!

Sounds Of Silence: The Best Noises For Sleep