Chances are you’ve played around with a sound machine before. If not, you’ve surely heard of them. Search YouTube and you'll find thousands of hours of sleep sounds: rainfall, ocean waves, fire crackling, whales, you know the drill.
But what about the color of sound? White noise, pink noise, brown noise – what’s the difference? And does it matter? We’ll break it down for you here.
What are sleep sounds?
Using sound to promote sleep may seem counterintuitive. While most of us prefer silence, certain sounds may be effective in improving sleep quality.
There’s a concept within the realm of sound where different frequencies and amplitudes are assigned specific colors to categorize and describe their characteristics. The most commonly known is white noise, but there are many other colors, too. Each color of noise has a distinct spectral distribution, affecting the perception of sound in unique ways.
The unique qualities of color noises make them versatile tools for creating auditory environments tailored to specific needs.
How do sleep sounds work?
Color noises are classified by their power distribution across the frequency spectrum.
Frequency in sound refers to the number of cycles or vibrations per unit of time that a sound wave completes. It is typically measured in Hertz (Hz), where one Hertz equals one cycle per second.
Different frequencies of sound can have distinct effects on the brain, influencing various cognitive and emotional processes. Sleep sounds can be used to promote feelings of relaxation and calmness, as well as drown out any background noise and quiet the mind in order to drift off to sleep.
White noise vs. pink noise vs. brown noise
Each color noise holds a different strength on the frequency spectrum, and that is where it gets its name. The most popular color noises for promoting sleep and relaxation are white noise, pink noise and brown noise.
White noise
White noise gets its name from the analogy to white light, which is a combination of all colors in the visible spectrum. This is because white noise contains equal intensity across all frequencies. Similarly, white noise is a combination of all audible frequencies.
The sound of white noise is often described as a constant hissing or static-like sound. It is often used to soothe babies because it is said to mimic the sound of amniotic fluid in the womb. Examples of white noise include:
- Radio static
- Television static
- The hum of a fan
- Hair dryers
- Vacuums
- Air conditioning
Pink noise
Unlike white noise, which has equal energy across all frequencies, pink noise has more energy at lower frequencies. The term "pink" comes from the idea that if you were to visualize the frequency spectrum of the noise, it would appear pink, with a more even distribution of energy.
Pink noise is often softer, flatter and quieter than other colors. Examples of pink noise include:
- Rustling leaves
- Steady rainfall
- Wind
- Ocean waves
Brown noise
Also known as Brownian noise or red noise, brown noise is a sound that is deeper and more bass-heavy compared to white or pink noise.
Brown noise is characterized by a constant power density per hertz, making it sound like a low-frequency rumble or a continuous, soothing waterfall-like sound. It has a lower intensity at higher frequencies. Examples of brown noise include:
- Rumbling thunder
- Heavy rainfall
- Waterfall
Other sounds to help you sleep
When choosing sleep sounds, it's important to consider personal preferences as different individuals may find different sounds more effective. Many people also benefit from experimenting with a combination of sounds to find the most soothing mix for their particular needs. Additionally, there are various apps and devices specifically designed to provide calming sounds for sleep.
Here are categories of sounds to help you sleep that go beyond white, pink and brown noise:
Nature sounds
Nature sounds are like bringing a piece of the outdoors indoors. Imagine the rhythmic crashing of ocean waves against the shore, the gentle pitter-patter of rainfall on your window or the soothing babble of a running stream. These sounds can transport you to a peaceful place, helping you unwind and relax before bedtime.
Instrumental music
Instrumental music is a timeless way to unwind. Classical music offers intricate compositions that can calm your mind, while piano melodies invite you to let go of stress and tension. Ambient tunes create a sense of floating in space, perfect for easing into sleep. And the smooth rhythms of light jazz add a touch of sophistication to your bedtime routine.
Guided meditations
Guided meditations are like having a friend gently guide you to sleep. With soothing voices and calming imagery, they help quiet your mind and relax your body. Whether it's a body scan or a visualization of a peaceful setting, guided meditations offer a structured approach to relaxation, making it easier to drift off to sleep.
Binaural beats
This is when two slightly different frequencies are presented separately to each ear. Some researchers believe that exposure to binaural beats can influence brainwave activity through a phenomenon called the frequency following response (FFR). This suggests that the brain tends to synchronize its electrical activity to the frequency of the perceived binaural beat and can therefore mimic brain waves in certain stages of the sleep cycle depending on the frequency.
White noise, pink noise, brown noise, whatever – incorporating sound into your sleep space can transform your nightly routine and enhance your overall well-being.You know what else can? Choosing the right mattress. Meet our organic bed-in-a-box here.
