When you are lying in bed, every single noise-from the creak(嘎吱声) of the bed to a whistle in your partner's nose-may keep you awake. You may find it hard to get a good night's sleep. Actually, you may just need more noise. While it may sound strange, it is scientifically proven that certain types of noise can help you sleep well. Specially white, pink and Brown noise can mask(掩饰) these sounds, creating a more harmonious background.
White noise contains sounds of all frequencies(频率) that humans can hear. But it comes across as a high-pitched buzz(声调高的嗡嗡声). That's because of the way your ears hear it. Basically, your brain strengthens sounds in higher-pitched frequencies. So while you are hearing sounds from a variety of frequencies, the highest frequencies tend to drown(淹没) the lower-pitched ones.
The pink noise balanced out the noise so that sounds of all frequencies are heard equally. The higher the frequency, the more its volume is decreased. To your ears, the sound is deeper and softer than white noise. Think of rain falling on the sidewalk or a gentle wind in the trees.
In a study at China's Peking University, researchers found that when people hear either pink noise or no noise during the sleep, 75 % reported more restful sleep with the pink noise. Brain activity monitors proved that people had 23 % more restful brain activity at night with pink noise and 45 % more restful sleep during naps.
Brown noise takes this concept to the next level, further weakening higher frequency noise to produce an even deeper and richer sound.
The color of noise that will help you get more sleep is the one you like the best. While pink and brown noises are deeper and more balanced than white noise, your personal sleep preferences will decide which one gives you the best sleep.