# What is pink noise?

https://hushmachine.com/sounds/pink-noise · Free; −3 dB per octave · Kallos Labs

> Pink noise is random sound whose power falls by 3 dB with each octave, so every octave carries the same energy. To the ear it sounds more even and softer than white noise, like steady rain or wind in leaves.

## What it sounds like

Softer than white, like steady rain.

## How Hush Machine makes it

Hush Machine filters live white noise so its power drops by 3 dB per octave (a Voss-McCartney or Paul Kellet filter, as the app plan sets out). The app's tests measure the slope to within 1 dB per octave.

## How people use it

- A balanced background for reading, work or sleep when white noise is too sharp.
- Room and speaker measurement: audio engineers use pink noise because each octave has equal energy.
- Layering under rain or a stream.

## Questions

### Why is it called pink?

By analogy with light: shifting white light's energy towards the low (red) end makes it look pinkish, and pink noise shifts sound's energy towards the low end in the same way.

### Is pink noise better than white noise?

Neither is better; they sound different. Pink noise sounds softer and fuller, white noise brighter. Many people pick pink because white sounds harsh to them.

### What is 1/f noise?

Another name for pink noise: its power is proportional to 1 divided by the frequency.