A Multicoloured Symphony of Sound Noises

A Multicoloured Symphony of Sound Noises

Sound noises, often referred to as ambient or background sounds, hold a unique place in the realm of auditory perception. These auditory textures, akin to the colours in a painting, encompass a wide spectrum of frequencies and amplitudes.

In the world of sound, beyond the symphonies and melodies, lies a sonic landscape that often escapes conscious attention—the realm of sound noises. These are ambient sounds that surround us, intricately woven into the auditory tapestry of our lives. Sound noises emerge from a myriad of sources, both natural and artificial. Think of the humming of your fridge, the sound of the rain or sea, the fan of your computer, distant voices and car traffic. It is a canvas splashed with colours, sound noises bring forth a palette of sonic hues, each evoking emotions and states of mind. They all contribute to the tapestry of sound noises and our auditory environment.

Good to note is that this article is about certain frequency ranges across the audible spectrum, not about we as human might consider as noise or the volume of sounds.

The Colours of Sound Noises

Much like colours in a painting, sound noises are diverse in their characteristics. The low rumble of a waterfall might elicit a sense of tranquility, while the rhythmic clatter of a train can evoke a contemplative mood. These auditory hues have been metaphorically associated with colours, such as the “blue noise” resembling the sound of ocean waves, or the “pink noise” akin to rainfall. These sonic shades offer a spectrum of emotional and cognitive experiences.

There are many coloured noises but the ones below are the most distinct:

1. Grey Noise:

Grey noise is characterized by equal energy per octave, rendering it perceptually flat across the entire audible frequency spectrum. It lacks the prominence of higher frequencies found in white noise.

Frequency Range: Throughout the entire audible range.

Use: Grey noise is often used for psychoacoustic studies, as it allows researchers to explore how humans perceive sound energy at different frequencies.

2. White Noise:

White noise exhibits equal energy across all frequencies, creating a consistent sonic spectrum akin to the static on a television or radio.

Frequency Range: Throughout the entire audible range.

Use: White noise is commonly used for sound masking, promoting concentration, and aiding sleep.

3. Blue Noise:

Description: Blue noise has a higher energy in higher frequencies, rendering it a sharper and more pronounced sound than white noise. It is akin to the sound of ocean waves crashing.

Frequency Range: Increases logarithmically with frequency.

Use: Blue noise finds application in audio testing, especially for assessing high-frequency capabilities of audio equipment.

4. Brown Noise:

Brown noise, also known as red noise, has more energy in lower frequencies (twice as strong as Pink noise), creating a deeper, rumbling sound reminiscent of a thunderstorm or a waterfall.

Frequency Range: Decreases logarithmically with frequency.

Use: Brown noise is favoured for relaxation, stress reduction, and aiding sleep. Recently a lot of articles have popped up of the use of brown noise to help focusing when you have ADHD.

5. Pink Noise:

Pink noise has equal energy per octave, resulting in a balanced frequency spectrum that decreases as frequency increases. It has a smoother and more natural sound compared to white noise.

Frequency Range: Throughout the entire audible range.

Use: Pink noise is beneficial for enhancing focus, improving cognitive performance, and aiding relaxation.

6. Violet Noise:

Violet noise, also known as purple noise, emphasises the highest frequencies, making it a sharper and crisper sound compared to white noise. It resembles the hiss of a high-powered waterfall.

Frequency Range: Increases logarithmically with frequency, with higher energy in higher frequencies.

Use: Violet noise has potential applications in improving hearing sensitivity and aiding auditory processing.

Deeper into coloured noise

In the book Sonic wonderland, A Scientist Odissea of Sound by Trevor Cox he mentioned that he moved his head from side to side, voices in the room change as if someone was rapidly altering the settings on a hi-fi’s graphi equaliser.  This colouration was caused by a change in the balance of the sound, with some frequencies being boosted while others were suppressed. In short he was experiences noises this is what he had to say about the colouration of noises:”

It might seem odd to talk about the colour of a sound …The link between colour an sound goes back many centuries, with Sir Isaac Newton spotting the similarity between the distance his prism spread out light colours and the lengths of strings needed to sound out a musical scale”

Trevor Cox mentions that also today, acoustic engineers use terms as ’white and ‘pink’ noise. In a way it is similar as he explains when paints are mixed together the frequency balance of the reflected light changes from the original colours presenting a different colour. He explains further that blue paint reflects light of a higher frequency than red paint and therefor acoustic engineers use colours to describe the dominant frequencies in sounds,

What is interesting is that he also found that sound most likely influenced the way our ancestors painted. He mentions acoustic archaeologist Steven Waller who wrote a paper on this subject. (We delve into this subject in another blog) apparently the sheer volume of evidence that prehistoric rock art was influenced by cave acoustics is growing. But Cox does refer to David Lubman, a retired aerospace engineer who has been applying acoustic science to archaeological sites, warns that correlation does not necessarily mean causation.

Benefits and Negatives

The benefits of sound noises are multifaceted. They can mask intrusive sounds, enhancing concentration and aiding relaxation. Studies (see below this article) highlight the positive effects of sound noises on cognitive performance and stress reduction. However, excessive exposure to certain sound noises can lead to noise pollution and even adverse health effects. Our world is increasingly becoming louder and louder. Interestingly enough these coloured noises can be used to mask the “noise” from the world around us helping us to relax or focus. Also there are more and more experiments and research is done to find the benefit of these noises for healing in hospitals, to enrich musical soundscapes and increase productivity in normal noisy environments.

Brain processing

The human auditory system’s response to sound noises is an interplay of neural processes. When exposed willingly to sound noises, the brain’s default mode network can deactivate, promoting mindfulness and concentration. Neuroimaging studies, such as those by L. Liikkanen (see the last one of the list, below this article), illuminate the brain areas involved in processing sound noises, shedding light on their cognitive and emotional effects. The world of color noise offers a diverse spectrum of auditory experiences, each with its unique frequency distribution, emotional impact, and cognitive effects.

Self Help versus the research

If you are inspired to start listening consciously to noises it is good to note, most scientific research on this subject is not a 100% clear on how often, how to use, what colour to use exactly for what kind of mental effect you want to reach. Wether it is to focus, to mask sounds or fall asleep or stay asleep, the best advice we can give you is to experiment with the different noises in different situations. You can use the description of the colours above as a starting guideline. Experiment with different factors: the colour, the volume and the exposure time and see what works best for you. Our tracks are made in such a way you can easily put them in a loop. To read further at the bottom of this articles are some interesting links.

You can purchase our album with the different noises here: @claudio

Interesting research and articles to delve into:

Spectral Content (colour) of Noise Exposure Affects Work Efficiency: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7986458/

Effects of masking sound on train passenger aboard activities and on other interior annoying noises: http://www.diva-portal.org/smash/record.jsf?pid=diva2:341431&dswid=-2379

Effects of sound source localization of masking sound on perception level of simulated tinnitus: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8795453/

Unintended Consequences of White Noise Therapy for Tinnitus-Otolaryngology’s Cobra Effect: A Review https://pubmed.ncbi.nlm.nih.gov/30178067/

Cognitive Performance and Sounds: The Effects of Lyrical Music and Pink Noise on Performance

https://inside.nku.edu/content/dam/gero/docs/NYSA/Nysav1/Chitwood_Cognitive Performance and Sounds.pdf

Different Effects of Adding White Noise on Cognitive Performance of Sub-, Normal and Super-Attentive School Children https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4231104/

The Effect of Noise Exposure on Cognitive Performance and Brain Activity Patterns: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6901841/

Background white noise and speech facilitate visual working memory: https://www.biorxiv.org/content/10.1101/2020.04.07.030114v1.full.pdf

Can pink noise help you fall asleep


Musical activities predispose to involuntary musical imagery


To read more in sound in general and also noises we can recommend: Sonic wonderland, A scientist odissea of sound by Trevor Cox

If you are interested in de description and the technical aspects of the colour noises we can recommend the wikipedia page https://en.wikipedia.org/wiki/Colors_of_noise#White_noise

Brainwaves, Binaural Beats 

Brainwaves, Binaural Beats 

Where do technology and sound meet and can actually influence our brainwaves? Binaural beats offer a realm of potential and have an ability to influence or more exactly entrain our mental states through electrical brainwave activity.

Science Behind Binaural Beats

The effect of binaural beats lies in their ability to tap into frequencies that are perceived, not heard, by the human ear. By playing two slightly different frequencies in each ear, the brain generates a third tone, unlocking aural illusions that influence brainwave activity to that frequency. For optimal effectiveness to produce these beats they require frequencies under 1000 Hz. By listening to specific binaural beats they can entrain your brain to a specific brainwave state.

Decoding Brainwaves

The interplay of neurons within our brains forms the basis of our thoughts, emotions, and behaviors. These brainwaves show that these neurons seem to converse with one another. They can be detected through sensors placed upon the scalp, (EEG) the measured oscillations are then categorized into bandwidths/brainwaves. Each brainwave range represents a different state offering a glimpse into the diverse tapestry of human consciousness. To give an example beta waves stand for alertness and are necessary for the normal busyness of life while delta waves often represent deep sleep. A bit below you can find a list with the different brainwaves and the binaural beats to possibly experiment with:

Unraveling the Historical Thread

The history of binaural beats traces back to the 19th century, gaining comprehensive recognition through Oster’s meticulous study in 1973. This auditory investigator capitalized on the brain’s response to subtly varying frequencies, producing vibrations now known as binaural beats. The difference between the two sounds must have a frequency difference of less than 30 Hz to allow our brain to perceive the third frequency consciously. Above 30hz it becomes a normal listening experience because beyond frequency differences of 30 Hz, the two tones are perceived separately. This threshold seems to vary depending on the stimulation technique that is used.

The Main Brainwaves

Delta: 1-4 Hz.
Delta is the lowest frequency state, and it’s linked to:

  • Deep sleep
  • Meditation
  • Cortisol reduction/DHEA increase

Theta: 4-8 Hz. Theta binaural beats are linked to:

  • Meditation
  • Deep relaxation
  • Creativity

Alpha: 8-14 Hz. Alpha brain waves are linked to:

  • Relax and focus
  • Reduce Stress
  • Increase learning capabilities
  • Flow

Beta: 14-30 Hz. Beta brainwaves are linked to:

  • Keeping your attention focused
  • Analytical thinking and solving problems
  • Stimulating energy and action

Gamma: 30-100 Hz. Is linked to:

  • Increased cognitive enhancement
  • Attention to detail, helping in memory recall <interesting research with Alzheimer>
  • A different way of thinking

Best for gamma up to 40HZ based on different research. And above 40 HZ the binaural beta is technically not a beat anymore.

Mental health

Our brainwave profile weaves with our daily experiences, shaping our emotional and neuro-physical health. Brainwave patterns can give us insight in a multitude of conditions, from anxiety disorders and sleep problems to depression and ADHD. Brainwaves offer insight into these facets of our mental and emotional health. To give a very simplified example if you have a lot of beta waves while you supposed to sleeping it will be difficult to sleep. This offers the door to improved well-being by experimenting with brainwave entrainment using binaural beats.

Using binaural beats

There is more and more research on using binaural beats (some is enlisted below this article). There are no documented side effects of using binaural beats but we do advice to use your common sense. Ensuring that your headphone sound levels remain safe is for instance crucial to avoid long-term hearing loss. (Yes you do need headphones to perceive the binaural beats). Consultation before using them with a medical professional is advisable for those with epilepsy, as research in this area is ongoing. Some studies hint at increased sensations of sadness or short bursts of anxiety during binaural beat listening, although the full extent of their therapeutic impact is still being researched.

Although binaural beats have been linked to enhanced emotions, and entraining brainwave states the response is subjective, making it essential to explore and find beats that resonate with one’s individual needs. So the real advice is experiment with the time, volume, the kind of beats and the individual frequency. To assist you in this as Flower of Sound, there is an album available with all of the individual pure frequencies per brainwave and an album that puts the whole frequency range within a specific brainwave in one track. Binaural Beats Full Spectrum Range can be categorised as a non-ordinary listening experience to experiment further with the power of sound.

Brainwaves and Immersive Soundscapes

This field of brainwave entrainment, also offers a new possibility where brainwaves merge harmoniously with immersive nature soundscapes. As listening to nature sounds comes with its own set of benefits. Nature Brainwaves merges these nature soundscapes by using microphones capable to record full 360 soundscapes in combination with binaural beats.

The idea behind this union is an immersive auditory listening experience that guides listeners to desired states of consciousness. As we listen to the binaural beats, the ambient immersive soundscape envelops us, mimicking the way living beings perceive acoustic spaces. This fusion offers a natural and less stressful alternative to traditional stereo signals so it can be used for medium to long listening sessions. Unlike some platforms that reduce the volume of these frequencies to minimize “annoyance,” Nature Brainwaves embraces their presence, allowing the binaural signal to be consciously and physically perceived.

Nature brainwaves and Binaural Beats Full Spectrum Range use 200 hz as a more pleasant and low but still hearable tone than higher frequencies that are less comfortable to listen.


About entrainment:
Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity, and the implications for psychological research and intervention


Scientific America (Auditory beats in the brain)


University of Birmingham


Massachusetts Institute of Technology


Modulatory Effect of Association of Brain Stimulation by Light and Binaural Beats in Specific Brain Waves


National library of Medicine

About the use of 40 hz