The symphony of silence.
The silence of white and brown noise.
By Dr.
Iman Fani.
In the dark rooms where I work as a radiologist,
I am accustomed to seeing the unseen.
Today we are going to apply the same lens to the world of sound.
We often think of noise as something to be avoided,
A distraction or a nuisance.
But in the world of neuroscience,
Certain types of noise act as a blanket for the brain.
You've likely heard of white noise.
Like white light,
Which contains every color of the visible spectrum,
White noise contains every frequency audible to the human ear at an equal intensity.
It sounds like the hiss of a radio or the static of an old TV.
Then there is Brown Noise,
Named not for a color,
But for Scottish botanist Robert Brown,
The discoverer of Brownian motion.
The haphazard motion of the molecules inside the liquid.
Unlike the teeny hiss of white noise,
Brown noise has more energy in the lower frequencies.
It sounds deeper,
Like the rumble of a distant waterfall.
A low-pitched roar of the ocean or the hum of a large engine.
Now let's talk about why it works,
The concept of masking and stochastic resonance.
How does a noise machine help us sleep or focus?
It comes down to two primary neurological mechanisms.
First,
For sleep.
This one is auditory masking.
Your brain isn't usually woken up by the volume of a sound.
But by the change in sound.
If you're sleeping in total silence and a car door slams outside,
The sudden spike in decibels triggers your brain's threat detection system.
White and brown noise create a sound blanket.
Reducing the contrast between the background and those sudden,
Unpredictable noises.
So the peaks and sparks get dampened.
The second more fascinating mechanism is for the focus.
This is stochastic resonance.
This is a phenomenon where adding a certain level of noise to a system actually makes a weak signal easier to detect.
In the brain,
This background noise can help prime your neurons,
Helping them focus on a specific task,
Like reading or writing.
By filtering out the internal neural noise that causes distraction.
One of the most important questions is,
Is it universal?
Does it work for everyone?
The answer is a firm no.
Research suggests that noise affects different brains in radically different ways.
For individuals with ADHD,
Attention deficit hyperactivity disorder,
White noise has been shown to enhance dopamine release and improve memory and focus.
So for ADHD,
The answer is yes,
It works.
For these brains,
The external noise acts as a stabilizer.
However,
For neurotypical,
Or super attentive individuals,
The same white noise can actually hinder performance.
Acting as an additional load that the brain must work to ignore.
The science for brown noise while buzzy on social media is still in its infancy.
While thousands swear by its ability to quiet internal monologue,
We lack the decades of clinical trials we have for white noise.
It may simply be that the deeper tones of brown noise are more pleasant and less uneasy.
Than the harsh hiss of white noise,
Making people more likely to use it.
And my personal answer is,
Yes,
Brown noise works better.
Than the white noise,
At least in case of sleep.
Now,
Another question.
Can noise be harmful?
Are there any risks?
As a physician,
I must address the safety of these tools.
The greatest risk is volume.
Some white noise machines and apps can reach levels over 90 decibels,
Similar to a motorcycle engine.
Constant exposure to noise above 70 to 85 decibels for 8 hours can lead to permanent hearing loss.
For infants whose ear canals are shorter and amplify sound,
The risk is even higher.
Loud noise has been linked to potential delays in auditory and language development.
But is it addictive?
No,
Not in a chemical sense.
But you can build a conditioned stimulus.
If you use it every single night,
Your brain learns it cannot flip the switch to sleep without that specific sound.
This is called habituation or simply building a habit.
So,
What's the best practice?
To use these sounds safely and effectively,
I recommend the following.
First,
Keep it low.
Never exceed 50 to 60 decibels.
The level of a quiet conversation.
Second,
Distance matters.
Place the device at least 7 feet or 2 meters away from your bed or your child's crib.
Third,
Experiment with them.
If white noise feels uneasy or sharp,
Try the sublime and grounded rumble of brown noise.
And also try a device that fades out the noise.
For example,
After one hour.
And does not suddenly stop playing.
The technique of fading out is actually less disruptive.
This is actually fascinating science.
We are only just beginning to understand the palette of sound and its impact on the human masterpiece.
I'm Dr.
Iman Fani,
Thank you for your curiosity and I hope this helps you find your perfect sound plan.
