An Exploration of Sound and Its Variants

It would have been around 12 years ago to the month that I first became aware of white noise. As a Mum to 6-month-old twins sleep was unsurprisingly in short supply. A visiting health professional suggested I tried white noise to lull these small humans to sleep. Now I’m not going to say it was a resounding success, or that as the white noise was switched on the crying instantly switched off, but it did seem to bring a general calm to some difficult times, for both babies and Mum. I began to experiment with the different colours of noise and the effects it could have on my brain focus, sleep and relaxation. 

What Colour is Noise?

The concept of colour in noise relates to the frequency distribution and the energy present at various frequencies. Each type of noise has a "colour" that describes its unique spectral properties:

• White Noise: Equal energy across all frequencies.
• Pink Noise: Equal energy per octave, decreasing power as frequency increases.
• Brown Noise: More energy at lower frequencies.
• Blue Noise: More energy at higher frequencies.
• Violet Noise: Increasing intensity with frequency.
• Grey Noise: Flat perceived spectrum adjusted for human hearing sensitivity.

White noise is a type of sound that is characterized by a consistent, uniform distribution of frequencies across the audible spectrum. It is often compared to the sound of a static hiss, like what one might hear from an untuned television or radio. The term "white" is used because the noise contains all frequencies within the range of human hearing in equal measure, akin to how white light contains all visible wavelengths.

Applications and Benefits of White Noise

White noise is widely used for various purposes, including:

• Sleep Aid: Many people find white noise helpful in masking disruptive sounds, promoting relaxation, and improving sleep quality.
• Concentration and Focus: It can create a consistent audio environment that helps individuals concentrate, particularly in noisy settings.
• Tinnitus Relief: White noise can help mask the ringing or buzzing sounds associated with tinnitus, providing relief to those affected.
• Sound Masking: In offices and public spaces, white noise is used to mask background noises, enhancing privacy and reducing distractions.

The Noise Rainbow

In addition to white noise, there are several other types of noise distinguished by their spectral properties. These include:

Pink Noise 

Pink noise is similar to white noise but has a more balanced, deeper sound. It features equal energy per octave, resulting in a frequency spectrum that decreases in power as the frequency increases. This type of noise sounds more natural and is often compared to the sound of steady rainfall or rustling leaves.

Brown Noise

Also known as Brownian or red noise, brown noise has even more energy at lower frequencies, creating a deep, rumbling sound. It resembles the roar of a distant thunderstorm or the hum of a large waterfall. Brown noise is often used to improve sleep and relaxation.

Blue Noise

Blue noise is the opposite of brown noise, featuring more energy at higher frequencies. This noise is less common but can be used in certain audio engineering applications where high-frequency emphasis is needed.

Violet Noise

Violet noise, also known as purple noise, increases in intensity with frequency. It is primarily used for audio testing and sound engineering.

Grey Noise

Grey noise is a variant of white noise that has been psychoacoustically modified to account for the human ear's sensitivity to different frequencies. This results in a noise with a flat perceived spectrum, sounding more balanced to the listener.

Conclusion

The different types of noise, from white to violet, illustrate the diversity of sound and its applications. Each type of noise has unique characteristics and uses, whether it be for sleep, relaxation, concentration, or audio engineering. Understanding these variations can help individuals select the most suitable noise for their needs, enhancing their auditory experiences and well-being. Listening to white noise can help the brain to focus by masking distracting sounds and creating a consistent auditory environment. This consistent background noise reduces the brain's need to process unexpected sounds, allowing it to concentrate better on the task at hand. The equal energy distribution across all frequencies in white noise creates a stable sound blanket that can drown out sudden, unpredictable noises. This effect helps prevent interruptions and promotes sustained attention, which is particularly beneficial in noisy settings like busy offices or public spaces. White noise can thereby enhance cognitive performance, support mental clarity, and improve productivity by minimizing external auditory disturbances. Exploring the individual colours of noise can further enhance the positive effects however with some providing more focused influence on brain performance. My go to colours are brown when working and pink for deep relaxation. 

Why not try out the different colours for yourself? Find out which ones your brain is more reactive to and discover your colour preferences for optimum performance and rest.