The Color of Noise

The colors of noise can be idealized similarly to the colors of a prism. White is the combination of all and black is a void of all. There is then the range in between. The color prism goes from red to violet and noise spectrum contains such colors as pink, blue and brown, all which affect listeners in different ways.

When you look at an audio wave, the two main components are the frequency and the amplitude. Frequency is how fast the wave is vibrating per second and the amplitude is the power or height of the waveform. For instance in music, the frequencies are laid out in a pattern that we pick up to create the harmonic structures of the song and the amplitude would be how loud.

Colored noises have been gaining popularity in recent years to calm the mind and help with concentration. There are even machines that generate certain tones and levels to help with insomnia. Now, if you “go down the rabbit hole” it has been said that certain combined tones can lead you into a trance or even hallucinate. Think about the very beginning of “The Matrix” movie where Neo is selling audio files. We are just going to be focusing on the basics here but feel free to keep researching about this fascinating subject.

White Noise

White Noise is generally the most familiar with people. It is a random mixture of all the frequencies that a human ear can hear. This kind of noise has equal volume throughout the entire frequency. An example would be TV static on an unused channel or a fan to mask out background sounds.

Pink Noise

This noise has equal energy per octave scale. This means that the volume decreases with frequency. Think about rising and lowering of the tides in the ocean. It is all bass tones with no treble. Pink Noise has also been studied as a sleeping aid, claiming that it can help put you into a deeper sleep, helping with an overall better night’s rest.

Brownian Noise

This type of noise is similar to Pink Noise but a bit deeper. Think ocean waves or a strong wind storm. Brown Noise is not actually named for the color but rather, the Brownian motion. This motion is also known as "random walk" or "drunkard's walk". It has been found useful for people to help them focus on a task.

Red Noise

Red Noise is also similar to Brown Noise. It is very bassy kind of noise that sounds like a low rumble. Think of a subway train or an air-conditioning system.

Blue Noise

This is just high-pass filtered White Noise that can sound screechy and artificial. Think the hiss of spraying water from a broken pipe. This is all treble with no bass tones. It will increase in volume and frequency.

Violet Noise

Violet Noise is also called purple noise. It is pretty similar to Blue Noise but a bit more intense. Instead of the spray of Blue Noise, it is similar to the sizzling of bacon on a griddle.

Green Noise

This color of noise can be found in the center of the sound spectrum. It is mainly associated with ambient nature sounds hovering around 500 Hz.

Grey Noise

This one will sound different to everyone every person hears on a different curve. It sounds the same at every frequency. Grey Noise is important though because it can help level out the sounds we do hear. For instance, if you have a ringing in your ear or are sensitive to sound, Grey Noise will help moderate what you do hear.

Black Noise

Did you not hear anything in the clip above? That is because Black Noise is complete silence. It is the void of all audio similar to the color black that is void of all colors.

Reference:

• https://en.wikipedia.org/wiki/Colors_of_noise
• https://web.archive.org/web/20050720074308/http://mv.lycaeum.org/M2/noise_ahf.html
• https://www.theatlantic.com/science/archive/2016/02/white-noise-sound-colors/462972/
• https://www.cell.com/neuron/fulltext/S0896-6273(13)00230-4?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0896627313002304%3Fshowall%3Dtrue