No doubt you've heard of white noise, the sounds that can help you block loud or distracting noises in order to sleep or concentrate. Well, it turns out that, depending on the type of noise you're trying to avoid, you may want to try some colored noise instead.
We're not talking ocean waves or thunderstorms, although those can also be quite soothing. True white noise sounds more like radio static: it doesn't contain the variations that nature's sounds often have (birds in the rainforest, anyone?), which can pull your focus to the recording rather than letting it fade into the background.
Without getting too technical, the colors of noise refer to their frequencies, i.e., the vibrations they produce. Think of sound as a wave that travels through the air and into your ear. The higher the frequency, the bumpier the wave, and the more high-pitched it sounds when it vibrates your eardrum. So if you're being distracted by a certain frequency of sound, say a deep, rumbling train, using a low-pitched brown noise will blend the train into a more continuous noise, making it much less distracting.
Here are the three most common colors of noise:
Although the term "white noise" has come to mean any type of masking sound, true white noise is the "flattest" noise, in that it contains an equal amount of energy across its frequency bands. That simply means it provides a continuous sound which covers a large spectrum. It's good for masking all types of sounds, especially if they're all occurring at once— city sounds, traffic, voices and sirens blaring — all this would be greatly improved with the addition of white noise.
Pink noise is similar to white, except it contains an equal distribution of energy in each octave — pink noise is calibrated to sound balanced to human ears. Emphasizing lower frequencies means pink noise sounds less "noisy" and more airy than white noise. If white noise sounds like static, pink noise is more like a waterfall. The pink tones are proven to be calming and still masks a variety of sounds, so it's great for alert yet relaxed concentration.
Brown noise lives in the lowest frequencies. It often sounds like a soft, deep rumbling. Warmer, and therefore soothing for kids and pets, brown sounds are great for masking low tones like thunder, trains (my particular annoyance), buses, or your neighbor's loud bass.
It may take some trial and error to discover the right way to mask your distractions, but luckily it's fast, easy and cheap to experiment with a variety of MP3 tracks. Try Simply Noise or even a You Tube search to hear the various colors of noise before you commit.