Using a noise machine to get a better night’s rest may sound counterintuitive, but listening to a uniform sound can effectively mask whatever’s stopping you from snoozing (i.e. a snoring partner or dripping faucet). Creating noise is strategic business, and just like colour, sounds have different sonic hues that can have a particular effect on us.
According to The Atlantic, audio engineering involves a rainbow of noise colours, each with one-of-a-kind properties that are capable of provoking specific feelings. It would explain why certain music amps us up or winds us down, or why a noise machine can help with sleep and concentration. While most of us are acquainted with white noise, there are two other notable coloured noises that works well for humans: pink and brown.
Firstly, sounds are composed of frequencies and waves, and the balance between them changes our perception of the sound being produced. White noise contains randoms sounds from all frequencies the human ear can hear (roughly 20 hertz to 20,000 hertz), just like how white light is all visible wavelengths of light we can see. Humans hear in octaves, i.e. the doubling of frequencies, which is why most perceive white noise as a fuzzy hiss or static that’s higher in pitch.
Pink noise, while technically still white noise, sounds less bright because the power of the higher frequencies is dampened, which balances out all octaves to be heard evenly. It can be heard as more balanced or flatter in comparison to the brightness of white noise. Pink noise has been an unsung hero in soothing people into deeper sleep and studies are showing that it can help with memory too.
The deepest is brown noise, which sounds like a low roar due its significantly lowered power and increased frequency. It’s been known to improve sleep and focus, and is not to be confused to be with the infamous “brown note,” which has been said to cause people to feel a rumbling in their bowels and, well… lose control. That myth has been busted.
Sounds are much more complicated than we think, each with their own hue that can provoke a corresponding feeling. White noise is a term more commonly shared, but a closer look and listen reveals what we hear isn’t actually what it seems to be. So the next time you listen to a 10-hour loop of a light rainfall or rushing ocean tides, rethink the colour you perceive, because it’s probably not white.