Noise can be a double-edged sword when it comes to sleep. Sudden, disruptive sounds can easily wake you, but consistent background noise can help you fall asleep faster and stay asleep longer by masking any jarring disturbances. This is where noise colors like white, pink and brown noise come in.

Understanding Colored Noise

The color of noise refers to the distribution of its sound frequencies. Think of it like the colors in light, where different wavelengths create different hues. For noise, the color depends on how much energy is present at different frequencies across the audible spectrum.

“Those who can benefit the most from using noise during sleep are those who are sensitive to noises or who live in places where there is more noise, such as an urban areas,” says Roneil G. Malkani, MD, a neurologist and Sleep Medicine physician and scientist at Northwestern Medicine who has done extensive research on sleep.

To hear examples of white, pink or brown noise, search for them on YouTube, apps or websites. There are a plethora of recordings available.

White Noise: The All-Around Masker

White noise contains all audible frequencies played at equal intensity. It sounds like a steady and continuous “shhhh,” like a gentle waterfall or static from an untuned television or radio.

It’s best for people who:

• Are light sleepers. The primary benefit of white noise is creating a consistent sound barrier that drowns out abrupt noises like barking dogs, traffic or creaking floors. Your brain is less likely to register these sudden changes that could otherwise pull you out of sleep.
• Need help relaxing. The steady, monotonous hum can be calming and helps quiet a racing mind, making it easier to relax and drift off.
• Have trouble falling asleep. By providing a consistent auditory backdrop, white noise can shorten the time it takes to fall asleep. This is especially helpful for those with busy schedules or limited sleep time.

Pink Noise: The Softer, Deeper Cousin

Pink noise also contains all audible frequencies but has more power in the lower frequencies and less in the higher ones. This makes it sound deeper, softer and often more natural than white noise. Examples include the rustling of leaves, steady rainfall or ocean waves.

It’s best for people who:

• Are sensitive to noise and find white noise too harsh. Many people find pink noise more soothing and pleasant to listen to for extended periods compared to white noise. It also helps mask disruptive environmental sounds, contributing to a more peaceful sleep environment.
• Have trouble getting deeper sleep. Some research suggests that pink noise synchronized to the rhythm of your brain waves can enhance deep sleep.
• Are older or have memory concerns. Pink noise’s effect on deep sleep can potentially support memory consolidation, especially in older adults.

“There’s much more research to be done to determine the optimal settings and methods of stimulation and determine the viability of the synchronized pink noise as a treatment,” says Dr. Malkani. “However, this is very exciting because this will allow us not only to understand the relationship between sleep and memory but also find new avenues of treatment or optimizing sleep.”

Brown Noise: The Deepest Rumble

Brown noise (also called red noise) has an even greater emphasis on lower frequencies than pink noise. It sounds like a deep, rumbling roar, similar to a strong waterfall, heavy rainfall or distant thunder.

It’s best for people who:

• Have high anxiety or stress. Brown noise’s low, consistent tones can be soothing and help reduce stress and anxious thoughts that make it hard to fall asleep.
• Are sensitive to low-frequency disruptions. Brown noise is particularly effective at covering up background noises like the starting and stopping of a furnace or air conditioner, which can be disruptive.
• Find white or pink noise too harsh. Its deeper, softer sound can help your brain settle down and transition into sleep by creating a constant, undemanding auditory backdrop.

“In essence, pink noise is similar to white noise but sounds a little bit lower in pitch. Red noise or brown noise is even lower,” says Dr. Malkani. “When using continuous background noise, it is important to keep the volume just low enough to be audible, but not so high that it would cause arousal from sleep.”

Finding Your Perfect Sleep Sound

While all three noises can be beneficial, the ideal one for you comes down to personal preference and life circumstances. Experiment with different types and volumes to see which sound helps you feel most relaxed and facilitates your best night’s sleep. Many apps and sound machines offer samples of each, so you can explore what works best for you.