I researched the two types of noises to find out which one is better to play on your sound machine while sleeping.

You might already be familiar with white noise, if you prefer the sound of a whirring fan to block out distractions at work. Maybe you even use pink noise, like the gentle crash of ocean waves ...

There are eight sounds to choose from which allows you to experiment and find which one works best: Waves, birdsong, rain, car journey, spaceship, white noise, pink noise and brown noise.

That's called destructive interference. And it's exactly what our noise-cancelling headphones are doing. Let's go back to those sound waves from before. See, sound waves, like light waves ...