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What is white noise? Why it is best for sleep?

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Noise is a very irritating sound. But there are some noises which are really good for us and good for sleep. They are called white noise. In this article, we will get to know what is white noise, what color noise is best for sleep, and what is white noise machine. Let’s deep down to it.

what is white sound

Sound, a god-gifted phenomenon, which helps not only just living beings but also the complicated machines to conduct. The sound we hear may be pleasant or unpleasant. According to the encyclopedia, unwanted, unpleasant sound or such acoustic phenomenon is mostly known as noise. It is actually a wave signal from a natural or artificial source that sometimes can be received and perceived by the human brain and sometimes the brain can’t. Noise can be divided into many categories according to its sources, specific signals, signal continuity, and other factors. Today we will discuss the color of noise.

Color of noises

Basically color of noise doesn’t mean the noise, as a tangible color, we can see. It actually uses the idea of color to narrate a certain frequency, amplitude, and a very own noise signal. Different colors of noise have different properties.

There are quite a few kinds of noise like

  • white noise
  • pink noise
  • blue noise
  • brown noise
  • violet noise
  • grey noise
  • black noise, etc.

They all have various properties and application areas.

But today we will discuss noises especially usage for sleeping or focusing for work.

What is white noise?

Apparently, white noise composes its name from white light. Both have some similarities. We know that white light is the mixture of seven primary colors of the spectrum. On the other hand, white noise is the mixture of all the sounds that humans can hear which frequency is approximately from 20 Hz to 20,000 Hz. All the waves of different frequencies generate a random signal. The signal having equal intensity at different frequencies can be also called white noise.

So, what does the white noise sounds like?

White noise has different frequencies. The frequencies are played in fast random succession and our brain combines these random fast-changing frequencies into a fuzzy hiss of static.

As white noise is a composition of several frequencies, it should be averagely pitched. But practically it sounds high-pitched. It is because of human anatomy. In a set of random frequencies, statistically more sound will seem higher-pitched to the human ear. Another reason is human brain amplifies sounds in the higher-pitched region making higher frequency in white noise seems louder than they really are.

Now Let’s talk about some other noise similar to the white noise.

Pink Noise

Pink noise is almost the same as white noise but takes human hearing into account and balances out of the frequencies so that all octaves are representing evenly. The frequencies played in pink noise are random but the volume of higher frequency is damped. So the higher the frequencies get the more volume lowered. Pink noise sound deeper and more balanced listening experience.

Brown noise

Mostly similar to the white noise and the pink noise, there is a noise called Brownian noise in short brown noise. It’s also known as random walk signals because the signal is most likely to the pattern of a random movement of particles in the liquid. The sound is deep – identical to ocean waves.


What color noise is best for sleep?

These three noises are very effective to do focusing on work, sleeping, Our human brain is especially attuned to detect changes in our surroundings if there is a low level of background music.

These white noise, pink noise, and brown noise are playing all frequencies which are muffling blankets of sound. The frequencies mask other noise or sounds and make them less momentous compared to the background. Which helps us to sleep or take a nap.

But of the three noises pink and brown noise has slightly got an advantage because of the moderate level pitched and well-balanced listening experience.

Apart from the sleeping thing, what really white noise is used for? Well, scientists have found some criteria and implementation areas in which white noise is applicable. Let’s talk about a few of them.


In music, the involvement of white noise is quite significant. It is used to produce electronic music. Other types of noise signals can be generated from white noise directly or indirectly.

It’s also used for audio synthesis in the higher noise content instruments like cymbals, snare drums. A basic example of white noise is a nonexistent radio station.

Electronic Engineering

The impulse response of an electrical circuit can be obtained from white noise which later used in amplifiers or other audio equipment. As for having a mixture of all frequencies in white noise, it is used to test loudspeakers and microphones.

Working Environment

A study showed that the white noise background simulation improves the working rate among secondary students with Attention Deficit Hyperactivity Disorder (ADHD). Many multinational offices and workstations use the masking background noise to focus on work and create an improving work performance.

An experiment shows that noise does have a relation with a learning environment. It generates more learning ability to a participant increasing the recognition memory slightly. The white noise is also used in the hospital to help the patient to relax. Another use is to calm the crying baby.

Besides these practical applications, there are some theoretical areas in which white noise is used like the random vector transformation, time series analysis, etc.

White Noise Machine

From the name, a white noise machine is a device that generates white noise. Actually, it generates not just white noise but also some other noise like the sound of

  •  ocean waves
  • waterfalls
  • raining, etc.

It is actually an electronic instrument. It may be produced the desired noise or maybe just a playback of a digital recording.

White Noise Machine Usage

  • One of the main use of this machine is for sleeping. Those who have trouble sleeping, use the machine. Its also used for power napping.
  • The psychologist uses the machine sound as background music to help the patient to concentrate on something.
  • It keeps the working environment fresh.
  • It uses in the hospital to help the patient to relax.
  • It keeps calming the crying babies.
  • Another use of the white noise machine is to test audio or sound samples.

So, noise is unpleasant but turns out that white noise is not unpleasant. It is more of a relaxing sound to remove the stress. In the end, we can say that the solution to annoying noise can sometimes be more noise-sounds that come in many colors.

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Rayhan Sarwar

I am a glass and ceramic engineering student at the Rajshahi University of Engineering & Technology (RUET). I enjoy exploring science and technology, which is why I chose to study engineering!

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