White Noise ~ Pink Noise ~ Brown Noise

White noise is a random signal having equal intensity at different frequencies, giving it a constant power spectral density. The term is used, with this or similar meanings, in many scientific and technical disciplines, including physics, acoustical engineering, telecommunications, and statistical forecasting. White noise refers to a statistical model for signals and signal sources, rather than to any specific signal. White noise draws its name from white light, although light that appears white generally does not have a flat power spectral density over the visible band. Continue reading

Pink Noise, or fractal noise, is a signal or process with a frequency spectrum such that the power spectral density (power per frequency interval) is inversely proportional to the frequency of the signal. In pink noise, each octave interval (halving or doubling in frequency) carries an equal amount of noise energy. Pink noise sounds like a waterfall. It is often used to tune loudspeaker systems in professional audio. Pink noise is one of the most commonly observed signals in biological systems. The name arises from the pink appearance of visible light with this power spectrum. This is in contrast with white noise which has equal intensity per frequency interval

Brownian noise, also known as Brown noise or red noise, is the type of signal noise produced by Brownian motion, hence its alternative name of random walk noise. The term "Brown noise" does not come from the color, but after Robert Brown, who documented the erratic motion for multiple types of inanimate particles in water. The term "red noise" comes from the "white noise"/"white light" analogy; red noise is strong in longer wavelengths, similar to the red end of the visible spectrum.

People Are Just Learning The Difference Between White, Pink, And Brown Noise   IFL Science - August 4, 2023

Most people have heard of white noise - a static-like sound produced when an old-fashioned television was on the fritz. But, did you know there are other color sounds? White noise (or broadband noise) is one of the best known of all color noises and the sound is produced by equally hearing all of the audible sound frequencies smushed into one. The reason why it is called white is because of how light works. The white light that we see is made up of all combined wavelengths of light, which is a similar concept to white noise. This accumulation of noise creates an intense, high-pitched sound. Interestingly, due to white noise being made up of many frequencies, it can be helpful to drown out other sounds and is used to help some people sleep.

Ellie's White Noise Machine

A white noise machine produces an air whooshing sound to help someone sleep - often blocking out external noises. It's very helpful for some people and annoying to others. It's all about the way your brain is programmed.

Many people like myself use a white noise machine. I've had mine for decades slept 9 consecutive hours. It may take a while of getting used to, but once you do, your brain will be conditioned to fall asleep once you close your eyes, relax, and allow the sound to put you to sleep.

Something unexpected happened the first time I used a noise machine. I had two visuals or memories. I was asleep on a spaceship moving through space. That quickly changed to the image of me asleep in some sort of simulation chamber on a spaceship drifting through space-time. Makes you wonder if reality is a dream from which we are back to awaken.