Benefits of Brown Noise
Brown Noise has an even deeper sound than Pink Noise and is prevalent in nature in the form of waterfalls and ocean waves. It is characterized by the roar of rushing water. Although Brown Noise is given a color like Pink and White Noise, it is actually named after a Scottish botanist, Robert Brown. The random motion of water in a stream exhibits a quality called Brownian Motion.
Are you beginning to hear about the health benefits of Brown Noise? My hair dresser swears by Brown Noise for sleep. She is also a very accomplished bass player https://towerdefense.bandcamp.com (it’s Nashville!), so the perceived boost of lower frequencies in Brown Noise probably suits her, along with millions of YouTube users. The hashtag #brownnoise has over 86 million views on TikTok. Why is Brown Noise of such interest to so many, and what are the benefits people are experiencing?
The term noise is derived from the Latin nausea, not an auspicious etymology, but we have settled on it for this application of sound therapy, nonetheless. Technically, noise is sound with a near equal amplitude across all frequencies, every frequency all the time at the same intensity. Perhaps you are familiar with noise machines and noise apps, which have become ubiquitous. There is an increasing amount of evidence that the Spectral Noises derived from White Noise, spanning Blue, Pink, Green and Red/Brown have subtle but tangible health benefits. Göran Söderlund, a researcher at the Western Norway University of Applied Sciences, has done 15 preliminary studies on the effects of broadband noise on people with and without ADHD. His research shows that people with ADHD performed better on memory and language tasks when they listen to Spectral Noise.
The reason may be related to the level of the brain chemical dopamine. Persistent dopamine release appears to be lower in people with ADHD. Söderlund theorizes that for people with ADHD, listening to broadband noise somehow causes the brain to mimic the effects of dopamine.
“What happens when you’ve been using noise, say, for three months?” Dr Sonderlund said. “Does it actually build up new pathways in the brain that make neural communication easier? My hope would be that actually if you use noise, maybe you could lower medication.”
It seems Brown Noise is having a moment. So what’s different about Brown Noise? The high frequency hiss factor of White Noise is rolled off a little harder to create the Spectrum of Red noise, 6Db (Decibels) per octave, to be precise. But what differentiates Brown Noise, which shares the spectrum characteristics of Red Noise, is that Brown also contains a random fractal element called Brownian Motion. And what is Brownian Motion? In 1827 Scottish Botanist Robert Brown noticed the random motion of pollen floating in suspension in water. He was unable to explain this phenomenon, but since he dutifully recorded it, the motion was named after him. Later research, including work by Einstein, confirmed that Brownian Motion was the result of a random jostling of particles in gas and fluids. Brown Noise is a deeper, more natural sound composed of random fluctuations in amplitude, meaning the sound waves are in a state of constant change. This fractal randomness has a soothing effect on our brains, making it easier to both relax and focus.
How is Brown Noise produced? The recipe for brown noise is this: Begin with White Noise, roll off the top end, and mix in random micro-fluctuations of intensity. (A ‘roll off’ is an engineering term, a tone control to decrease the higher frequency sound, causing a perceived boost of the low frequencies.) Nature does this very efficiently in the flow of water or in the random roar of steady rain. This translates to sound, or Spectral Noise, when the sound source has a characteristic roll off of the high frequency hiss and contains more low rumble or roar and also has a random fractal element that is the result of motion, such as in a waterfall or ocean waves. The low frequencies of Brown Noise are a little more enhanced than Pink Noise due to this stronger attenuation of the high frequency hiss. Pink Noise rolls off the high end at 3Db per octave, while Brown Noise rolls off at 6Db per octave. Since decibels are logarithmic this difference is quite pronounced. Brown Noise sounds deeper and darker and lower. Added to the more pronounced low frequency sound, Brownian motion is a subtle spatial element. For a sound to be true Brown Noise or Brownian Noise it needs to be either derived from natural sources, such as a stream or waterfall, or filtered synthetically to replicate the random motion of molecular jostling.
This random, fractal noise has gained a huge following on TikTok, YouTube, and numerous sleep apps. Because the lower frequency range of Brown Noise aligns well with the human hearing mechanism, it is perceived as more relaxing. The added element of Brownian Motion adds random fractal variance that we also find restful when we encounter such sound in nature. The combination of enhanced lower frequency sound (soft roar), in conjunction with the roll off of harsher sounding high frequencies (hiss) as well as the added randomness of Brownian Motion makes Brown Noise a potentially more potent therapeutic sound than the other Spectral Noises.
In other contexts randomness has been shown to have a beneficial effect, particularly in the realm of creativity. The human mind is a pattern-seeking device. We are exquisitely tuned to pattern recognition. Randomness disrupts patterns and may facilitate a letting go, a shift from left brain analysis to right brain spaciousness, which activates the portal to the relaxation response.
The first most obvious use of Spectral Noise is sleep. White Noise machines have been around for a while, and increasingly they have been supplanted by noise apps and YouTube as tools for curating a sonically safe sleep zone. While more health related research has been done using White and Pink noise, the general consensus is that Spectral Noise can affect the “complexity synchronization of brain activity and sleep consolidation.”
https://pubmed.ncbi.nlm.nih.gov/22726808/
In other words, by synchronizing brainwaves it is possible for the brain to enter a more ordered state. Working like a mantra in meditation the steady sound of Spectral Noise allows the mind to focus on one external stimulus and calm the clutter of thoughts that might keep someone awake. It is likely that consistent use of a chosen color of noise will establish a pattern of association, a kind of Pavlovian response, so that just turning on the noise will facilitate a relaxation response.
Who knew there was such a wide world of noises and so much more to explore? I have intuitively used Brown Noise in my healing music for years. I am drawn to the subtle randomness of water in its many forms, rain, rivers, and ocean. I have experienced the therapeutic effects in both my own healing and that of my clients. I have utilized Brown Noise and Green Noise gathered from the New Zealand rainforest extensively in my latest project, Forest Bathing. I believe many of the known benefits of spending time in nature are related to the immersive sound experience of the majestic symphony of oceans, rivers, and birdsong. It is good to know that my creative instincts, and the intuitive knowing of my hairdresser, as well as the preferences of millions of TikTok, and YouTube users can now be validated by scientific research.
Notes:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7986458/ Spectral Content
(colour) of Noise Exposure Affects Work Efficiency
The effect of “…Pink noise might be due to neurons in the hypothalamus synchronously resonating with pink noises in the low oscillation frequency band, making slow rhythms and dominating brain waves. In addition, the power density of high frequency in [Brown] noise is even lower than in Pink noise and may therefore affect neurons in the hypothalamus even more, leading to information more speedily reaching the cerebral cortex through the hypothalamus and to faster transmission of motor messages through the hypothalamus.
