If you ask TikTok or YouTube, falling asleep requires a rainbow of sound. Beyond well-known white noise, there’s now pink, brown, green, and more.
But what do they mean, and who’s capitalizing on it?
How quickly a sound wave vibrates…
… is its frequency, which is measured in hertz.
- One vibration per second equals one hertz
- Humans can hear between ~20 and 20k hertz
- The higher the frequency, the higher the pitch
A sound’s color depends on how energy is distributed over its frequencies. With white noise, it’s evenly distributed across all audible frequencies (e.g., a fan, TV static).
What other colors are there?
- Pink: Energy is more intense at lower frequencies for a deeper sound (e.g., steady rain, wind)
- Brown: Similar, but even deeper (e.g., thunder)
- Green: Mid-range frequencies (e.g., ocean waves)
- Black: Silence.
Here’s a handy video demonstrating several colors.
What’s the benefit?
Most obviously, they mask other sounds, which helps people trying to sleep or focus in noisy environments.
Some studies have also found that certain colors may help us remain in deep sleep for longer or improve executive function.
With all these new color fads…
… come new products. White noise machines are adding other colors, while myriad apps offer soothing sounds. For example, BetterSleep offers custom sleep mixes, stories, meditations, and tracking. More features unlock for paid users.
YouTube channels, like “Relaxing White Noise,” have millions of subscribers, while podcasters are making bank with noise streams. One told Bloomberg he makes $18k+/month.
BTW: Sleep experts suggest setting a timer so that whatever noise you choose eventually turns off. Constant noise, even helpful ones, can be disruptive.