The Colours of Noise - Brown
We know that noise, like light, can be thought of as occurring on a colour spectrum. The spectrum begins with white noise, which is a uniform mix of many frequencies. Because white noise is polluted by so many different frequencies it has a low sound profile, meaning that it needs to be filtered to make other sounds more audible to the human ear.
Our ears pick up a disproportionate amount of high frequency sounds in white noise, so to make it sound more balanced we need to isolate and boost lower frequencies. Just as you might change the colour of light by filtering it through a coloured screen, filters can be used on types of noise to alter the sound quality. Another term for filtered noise is coloured noise.
After white comes pink noise, which is arrived at by boosting the bass frequencies in white noise. After pink comes brown noise, which involves a stronger energetic shift toward the low end of the sound spectrum.
Brown noise - unlike the rest.
Brown noise is a tricky one, because it’s not technically a noise colour. Unlike the others, which take their terminology from the spectrum of light, brown noise is named after a concept in physics called Brownian motion.
The phenomenon was first observed by Scottish botanist Robert Brown, when he was studying particles trapped in pollen cavities suspended in water. Looking at slides under a microscope Brown observed that the particles moved through the water with what seemed to be a will of their own.
Further study identified a collision between the pollen particles and water molecules, causing them to move. Brown noted the phenomenon, which was later expanded into Brownian theory by physicist Jean Perrin in 1908. It was considered crucial evidence in proving that atoms and molecules exist.
What does this have to do with sound? Brown noise is named after Brownian motion because its signal follows a similar pattern. Brown noise is an even stronger movement to the deep end of the sound spectrum. It is often described as a rumble, like thunder or heavy rain.
The healing benefits of brown noise.
If you’re into noise therapy, brown noise is said to have a range of healing and stress reducing properties. People report that brown noise helps them concentrate, and it has also been observed to reduce symptoms of anxiety. It is one of the more useful noise colours and can be used to boost relaxation and focus, and as an accompaniment to productive exercise, study and meditation.
Alternatively, you might be into no noise at all. That’s where we come in! Attenuators control unwanted noise, so you can appreciate the sound of silence. With all our manufacturing and design done in Australia and a quick turnaround, it won’t take long to start controlling noise on your next project.