The term 'white noise' is easier explained by taking a closer look at the name itself. White is a color that exists not because it has no (or lack of) color, but because it contains all the colors. This can be shown by a simple disc and thread.
Take a disc and divide it into equal parts through the center. Paint each section with a color from primary and secondary colors. Pierce the center and put a string through it. Twist the string along the ends, so that the disc spins. You'll see that all the spinning colors mix and merge to reveal the 'color' white! And this exact principle is used to define white noise.
So there you have it - white noise is nothing but a singular sound or noise created from the combination of all frequencies within the audible human range (roughly 20 hertz to 20 kilohertz).
Sources and Causes of White Noise
White noise being nothing but the superimposed audio waves of multiple frequencies, the simplest explanation for its cause would be the startup of a number of single frequency sources, or even a generator that produces multiple waves of random frequencies.
The natural sources of white noise are basically multiple 'noises' of the same type coming together to create a cacophony that no one wants to listen to. It can be either that or something that conjures up multiple frequencies, that together result into a sound that some may find soothing.
So the natural sources are mostly everyday objects or natural phenomenon, that create multiple frequencies as they function. Examples of that would be a table fan or a radiator, or the gargle of a small waterfall.
These are nothing but all the above everyday sounds you hear, produced 'artificially'. The purpose of artificial white noise generation emerges from the idea of fighting sound with sound. It can be produced using artificial synthesizers, to help sound engineers create a range of primarily 'static noise', like the breaking of ocean waves or the whoosh of a flying object.
The laws of audio harmonics make random white noise sound to human ears as a constant high pitch scream, but it does contain low frequency waves too. By using white noise generation kits, it is possible to generate and manipulate the noise to make it around a particular frequency. This is a very important aspect, which is used to mask or cancel any particular noise in your surroundings. These machines or CDs are sold almost everywhere now.
White Noise and Tinnitus
Tinnitus is a condition in which you constantly hear a high pitched ringing, crackling or buzzing in your ears. It mostly happens whenever there is an absence of surrounding noise. Tinnitus has multiple causes- they range from any damage to nerves around the ears, exposure to sudden loud noises, head and neck injuries or Ménière's disease. Tinnitus is also directly linked to stress, so the more stress you're under, the stronger the ringing noise in your ears.
One of the solutions for tinnitus is artificial white noise. It can mask the sound caused by tinnitus and thereby, reduce discomfort by a large extent. There are several audio tracks specifically help in relieving tinnitus.
White Noise in Electrical Equipment
Your radio, Television and computer speakers are all susceptible to generate static. This can happen because of many reasons. They include radio signal interference, which is caused by any electronic device that employs digital frequency generators. If the voltage applied to these generators is high enough, the vibrations of the waves will disrupt any signal reception close by.
Another cause is the Johnson sound- for any electrical conductor, the electrons may get disrupted from their relative state of equilibrium and get agitated. they then proceed to vibrate at high speeds to produce white noise.
Daily Uses of White Noise
There are two kinds of generators available - the ones that produce pure white noise and the ones that produce masked white noise of particular frequencies. The concept is useful for noise cancellation of any unwanted sounds from external sources.
For Improving Concentration
An example for this would be the table fan in your room, which can block out the noise from the television in the next room. Similarly, the machines or audio tracks are used to cancel certain external noises, like blocking traffic noise outside your car, or reducing the noise of a party next door.
For Better Sleep
Audio files for specific kinds of white noise blocks out all other sounds that may disturb your precious sleep. Buyers can choose between a wide range of natural sounds imitated on audio files using white noise, like fans, waterfalls or even ocean waves. It does not have any known side effects on the human ears and can be used for putting babies to sleep too. These tracks emulate anything from the sound of raindrops on the roof of a car to vacuum cleaners and maternal heartbeats.
All in all, what white noise provides for the human ears can go a long way in terms of enduring care for yourself. It can therefore go either way to trouble us or provide us with comfort. It is the noise that provides you with the silence for a strenuous task or for sleeping, or even just to get away from the annoyances of the real world. White noise, at the end of the day, will remain the inaudible tool of comfort.