What’s the difference between white noise and pink noise?
White noise refers to a type of sound that's an equal intensity across all frequencies audible by the human ear; similar to white light, which contains all visible light at equal intensity. White noise is produced by randomly generating noise across the entire sound spectrum, and it ends up sounding like radio static, which some people enjoy as background noise, while others find it irritating.
White noise has equal power per frequency, while pink noise has equal power per octave.
Here's an example: the difference between 5 Hz and 10 Hz is one octave, as is the difference between 50 and 100 Hz. But, in terms of absolute frequency, the difference between the first two is 5 Hz, whereas the difference between the second two is 50 Hz. In white noise, the difference is obvious, but in pink noise, they’re both one octave apart, so they’re functionally the same.
This is the major difference between pink and white noise. In white noise, the power is constant, but in pink noise, as the numbers get bigger, the difference in power becomes smaller, so the higher-pitched sounds are softer.
Because the lower frequencies are louder than the higher frequencies in pink noise, it sounds less abrasive and leads to a better night's sleep. Less like radio static, and more like leaves rustling.
Examples of Pink Noise in Nature:
- Steady rain
- Wind blowing through trees
- Rustling leaves
- Ocean waves hitting the beach
Are there other colors of noise?
There are indeed. The colors of noise include:
- White noise: equal power through frequency, like television static
- Pink noise: equal power through octave, like steady rain
- Brown noise: even more low frequency than pink noise, like thunder rumbling
- Blue noise: emphasizes the higher frequencies instead of the lower ones, like water hissing out of a spout
Why is pink noise good for sleeping?
Pink noise has been found by many studies to be the most soothing background sound. Not only that, but studies have also shown that going to sleep listening to pink noise from a sound machine helps improve memory the next day and could have long-lasting positive effects on memory and concentration.
It can be seemingly hard to find readily available sources of pink noise. Luckily, the Yogasleep Go, Yogasleep Nod, and Yogasleep Soundscene provide pink noise, and the Yogasleep Duet and Yogasleep Dreamcenter offer multiple pink noise options.
Often, other noise colors are lumped under the "white noise" umbrella, because it is a common term people understand, but the distinctions are important. Understanding what noise colors are helps you understand what color of noise is best for you.