Have you heard of “white noise”? People sometimes turn that staticky sound on to help themselves sleep. But now scientists are excited about noise of another color: pink.

Pink noise is similar to white noise. White noise is the sound you might hear on a radio or TV that’s not tuned to a channel.

Sound engineers say white noise has “equal volume across all the frequencies audible to the human ear.” So white noise combines all the frequencies of sound at once. (Frequency determines the pitch of a sound. The pitch is how high or low the sound is.) It jams your ear full of vibrating sounds at an even volume. This can block out background sounds that might keep you awake. It gets its name from white light, which contains all the visible color wavelengths.

Some people think white noise can sound harsh. Pink noise sounds lower in pitch. It turns down the volume on white noise’s higher frequencies. It’s more like the natural sound of rain or the ocean. Brown noise sounds are even lower. They give a pleasing, soothing rumble like gentle, far-off thunder.

So now there’s a growing buzz around pink noise. And brown noise too. Can these other colors help us relax?

It’s hard to say for sure. The science is new. Only a few small studies support it. But that hasn’t stopped thousands of people from listening to hours of these colorful noises online.

Scientists at Northwestern University study pink noise specifically. They wonder: Can short pulses of pink noise improve the slow brain waves that happen during deep sleep?

In small studies, pink-noise pulses show promise. Scientists think they may improve memory and help people relax.

The hearing ear and the seeing eye, the Lord has made them both. — Proverbs 20:12