The science of noise colors: why white noise makes you sleepy and blue noise helps you focus

A woman in bed wearing headphones and working on a laptop while taking notes.

I’ve always loved the sound of green noise while I work. It feels like my desk is surrounded by trees or positioned next to a waterfall. Something about it quietens my mental chatter and helps me focus, which is why I often play it in the background when I’m writing. But a few weeks ago, something unexpected happened.

I was deep in thought, not noticing the transitions between the green noise tracks Spotify was playing, when I suddenly felt sleepy. That’s when I realized the noise had shifted – from green to white. My productive focus had faded into a gentle drowsiness.