(How stuff works)
White noise is a type of noise that is produced by combining sounds of all different frequencies together
White noise refers to a noise that contains all frequencies across the spectrum of audible sound in equal measure. Because white noise spans multiple bands of sound, it is sometimes referred to as broadband noise. Anecdotally, people often liken white noise to the static that comes from an untuned radio or television.
You may have heard of white noise. The steady, static-like sounds from it can drown out disturbing noises and help you sleep better. But have you heard of pink noise and brown noise? Growing research shows that these lesser-known colour noises can also help calm you or improve your sleep quality.
Here’s a look at different colour noises and what they can do for you.
White Noise
It’s the most popular type of colour noise. It contains all frequencies
found in the spectrum of sounds you can hear in equal parts. It’s often called “broadband noise.”
White noise uses a mix of sound frequencies to create a static-like sound. It can be intense and high-pitched, like a fan, air conditioner, or a vacuum.
Studies have also shown that it can help:
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Improve sleep
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Reduce crying in babies
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Improve your wok performance
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Lower ADHD symptoms
Other studies have found that many people find that white noise has a positive effect on them. But experts say they need more proof.
Pink Noise
Pink noise is a constant sound in the background. It filters out things that distract you, like people talking or cars going by, so they don’t interrupt your sleep. You may hear it called ambient noise.
Like white noise, it’s a steady background hum that may give you a better night’s sleep. But it uses deeper sounds and lower sound waves, so it may be gentler and more soothing. Basically, pink has a lower pitch than white noise.
Pink noise uses a consistent frequency, or pitch, to create a more even, flat sound, like a steady rain, wind rustling through trees, or waves on a beach. Its added depth and lower waves filter out higher sounds. As a result, you hear more relaxing, lower-frequency sounds.
Brown Noise
Brown noise, also called red noise, produces a rumbling sound that’s deeper with a bass-like tone than pink or white noise. The sound level (decibels) decreases as the frequency goes up more than it does in pink noise. It’s similar to a steady heavy rainfall or a shower with good pressure. Some sleep apps use this sound instead of pink noise to give it a deeper, grainier effect.
Studies show that brown noise might help lower symptoms if you have ringing in your ears. It’s also shown to improve your thinking skills. More research is needed to see if and how brown noise affects sleep.
Other Colours of Noise
Besides white, pink, and brown noise, there are other colour noises that aren’t related to sleep. These include:
Blue noise
Its power increases as the frequency goes up. Blue noise sounds slightly shriller than pink and white noise. Imagine the hissing noise you hear when a water spray is turned on.
Violet noise
Also called purple noise, it’s the opposite of brown noise. The volume goes up when the frequency does and it gains power faster than blue noise. It’s one of the higher-pitched colour noises. It’s often used to treat tinnitus a condition that causes loud ringing in one or both ears.
Grey noise.
This produces noise at higher and lower frequencies but not so much in the middle frequencies. It’s similar to white noise, but more balanced.
Can White, Pink, and Brown Noise Help You Sleep?
For some people, the grainy static sound you hear in white noise can improve sleep. It helps by masking the background noise and tuning it out. One recent study found that 38% of people fell asleep faster listening to white noise.
Pink noise reduces the difference between the background hum and loud, jarring noises that jolt you out of sleep, like a door slamming, a car horn honking, or someone snoring. So it may help you fall asleep faster and keep you in a deep sleep longer. You may also feel more rested when you wake up.
There isn’t much research yet on exactly how pink noise works and how well it helps you sleep. One study found that it lowered brain activity and led to more stable sleep. Another study found people who used it slept more deeply.
Studies are limited, but pink noise may also boost your memory. A recent study found that older adults who used it at night did better on memory tests the next day.
We need more research to find out how pink noise affects your sleep, focus, and memory. But it’s safe and has no downside, so you may want to try it to see if it helps you.