The Different Colours of Noise and their Effect on Sleep

If you find yourself sleepless at nights and tossing and turning uncomfortably in bed, you’re not alone.  The inability to land a good night’s sleep can affect other facets of your life. For example, you may find it hard to focus at school or office. Prolonged sleep deprivation can also adversely impact your physical and mental health. 

Quite often, those struggling with insomnia or interrupted sleep are recommended white noise machines. However, that’s not the only sonic hue that can improve your sleep. Several familiar, consistent, and comforting sounds can help you relax and sleep better. 

Here is a lowdown on the various sonic hues and how they affect your sleep.

Understanding Sound: A Breakdown of the Sound Waves

Sound waves can essentially be deconstructed into two components: Frequency or Wavelength, and Amplitude.

  • Frequency: It refers to the vibrations per second and is measured in Hertz. Wavelength is the time taken by the vibration to complete one cycle. Wavelength and frequency are inversely related to each other, and they both determine the pitch of the sound wave.
  • Amplitude: It is an expression of the wave size. It is also known as the power of the soundwave and is measured in decibels. Amplitude controls the volume of the sound.

The colour of any sound primarily depends on the above two factors. 

Colors of noiseSource

Different Sonic Hues: White, Pink, Brown, and Blue

Before you are ready to get your hands on the best sound machines available in the market, you need to understand which ones fit your requirements. To help you with it, here is a list of the various sonic shades:

White Noise

What white is to colors, white noise is to sound. The white noise spectrum contains all the bands of frequencies in equal intensities. It has a flat spectral density, and white noise is within the 20Hz to 20kHz frequency range, which makes it audible to humans. It is the commonest noise spectrums used in the best sound machines.

The brain cannot hear different sources of frequency, due to which White Noise can block out every other background noise. Due to this virtue, it is highly recommended for those with sleeping difficulties and conditions like insomnia or tinnitus. 

Common sources of white noise include:

  • The whirring of the fan
  • Television or radio static
  • The hissing of a radiator
  • The humming of an air conditioner

Pink Noise

Pink noise, also known as inverse 1/f noise or flicker noise, has emerged as a potential sleep aid since various studies indicated that it has the ability to induce stable and deep sleep, which boosts memory and mood. It is deeper than white noise with a deep bass base and appears louder at lower frequencies. Unlike white noise, the frequency is not distributed throughout pink noise, and its spectral density decreases by 3dB per octave. It is highly effective in blocking out low-frequency background noises.

Natural sources of pink noise include:

  • Steady rainfall
  • The rustling of leaves
  • Heartbeat
  • The steady blowing of the wind

Brown Noise

Often referred to as red noise, brown noise derives its name from Brownian motion, which is the movement of particles in a random and speedy manner within a liquid. Hence, it is also said to replicate distant underwater ambient noises. Think of it as the sound you hear when you place a conch shell to your ear.

Brown noise is a deeper version of the pink noise, with a spectral power density decrease of 6dB per octave. Much like pink noise, it is more powerful at low frequencies. Due to the reduction in frequency, brown noise is capable of boosting concentration and helps maintain focus. Thus, it is not only useful for sleeping but can also help with studying.

Common examples of brown noises are:

  • Powerful waterfalls
  • Deep thunder
  • Low roaring

Blue Noise

Considering that blue is the opposite of red, it is safe to assume that blue noise is the exact opposite of pink noise. Blue noise lies on the colder spectrum of sound and emphasizes higher frequencies. Thus, the higher frequency results in greater amplitude. The power spectral density of blue noise increases by 3dB per octave.

Blue noise can help those who are sensitive to high-pitch sounds as it can effectively mask them. It is also commonly used by digital audio and video processing experts, who mix blue noise to audio tracks to smoothen the sound and prevent colour banding. This process is known as dithering.

Which Colour Noise is the Best for Sleep?

Given the popularity, so far, it appears that white noise machines emerge as the best sound machines for those looking to get a good night’s sleep. However, pink noise offers to help with sleep deprivation while also improving memory, making it a close second! 

At the end of the day, while certain shades of noises can aid with sleep, it is not a miracle solution and must be paired with good sleeping habits. These include establishing a comfortable sleeping environment, setting up a bedtime routine, turning off bright lights, and following a sleep schedule. Through these measures, you can implement robust sleep hygiene that will always wake you up feeling like you’re ready to conquer the world!