A few years back, I started to search about various kinds of noises to help people sleep better, I explored three main types, i.e white noise, brown noise and pink noise. Where I got stuck really badly, was the point when I had to decide about the type of noise I’ll be using as a sound to help me get my baby,as well as myself, to fall asleep in a relaxed way. The types of noises I found were helpful:
- White noise
- Pink noise
- Brown noise
Now you must be wondering what this is all about. Let me explain the theory behind the use of noise and its splitting into various types.
Actually noise as a whole has been defined as a mixture of various sound frequencies that vibrate at various levels, and all these frequencies are said to make a particular kind of noise.
When a spectrogram is obtained for various noise types, they give specific colors depicting the nature and density of the noise being produced. On a spectrogram you can see the colors blue, violet, white, pink, brown/red, or orange. In this case,we will only be discussing the three I have analyzed already—the pink, the white, and the brown noise—while ignoring other colors for now.
The white noise is a kind of noise where there are sound waves of varied frequencies, but which have the same sound power or energy to give a flat sound spectrum when produced. The white noise is valued as β=0, and is less dense. You can see the graphical representation here:
While the brown noise can be explained on the basis of Brownian movement theory where the sound waves travel with a 6dB decrease per octave and is softer as well as denser as compared to the white noise as well as the pink noise. The energy of the sound is higher with lower frequencies.
The pink noise is also known as flicker noise or 1/f noise. It falls 3 dB per octave and 10db per decade, which means it becomes dampened as the frequency increases.
These noises are also softer and more mixed as compared to the white noises.
Here on the left hand side you can see the pink noise which is denser and deeper while on the right hand side you can observe the less dense and more visible noise waves.
Now, the question comes, what are the differences in white noise, pink noise, and brown noise?
Here is a table to explain the phenomenon
|Properties/ Noises type||White noise||Pink noise||Brown/red noise|
|Color of the spectrum||Unidentified/white||Pink||Brown or red|
|Energy per octave or decade||Energy remains constant with the increase in frequency||Falls 3DB per octave||Falls 6DB per octave and 20 DB per decade|
|Pathway||Straight||Linear||Slightly curved, but linear|
Concluding the three noises, and their characteristics, it can be said that the pink noise is denser than white noise and brown noise gets denser than pink noise as the frequency increases. And what happens is that the sound becomes softer and has less power to cover or counter attack the noise around you, that is bothering you or that you need to mask.
Why I chose the white noise
I chose to use white noise because it has the ability to cover and mask a wide range of frequencies and can bring the effects down to a particular level and, in addition,it creates a well-balanced environment around you that will keep you calm and focused.
Some people do think that pink and brown noises can be effective, but I don’t agree with that because they are softer and can only help in soothing your nerves, and are not as effective for sound masking or noise reduction. Meanwhile,white noise is helpful and can work in a dual fashion, reduce noise and sound effects, mask unwanted sounds, as well as soothe your nerves to help you relax or focus better.