When searching for white noise to fall asleep to, put a baby to sleep, or relieve stress and anxiety, you may have come across other noises labeled as “brown” or “pink” noise. But how does white vs brown, or white vs pink noise compare to each other?
First, what exactly is white noise?
White noise is a specific type of noise that contains all the frequencies of sound that we can hear, just like white light includes all the colors on the spectrum. Some people describe it as having a similar sound to static or a hissing sound, like an old television or radio tuned between stations.
Now, let’s talk about how different sound frequencies create white noise. White noise is supposed to have equal energy at each single frequency (same energy at 100 Hz, 200 Hz, 1000 Hz, 5000 Hz, etc.). This might seem like some kind of sorcery, but it’s just the way the energy is distributed across the frequency spectrum.
When you combine all these frequencies together, with equal energy at each frequency, you get a sound that has a constant power spectral density. This means that the energy is spread evenly across the entire audible frequency range. The result is a sound that appears to be random and has a “hissy” quality to it, which we call white noise.
Pink noise vs white noise
Pink noise, sometimes called “1/f noise,” has equal energy per octave, meaning that the energy in each octave is the same. This results in a noise that has more low-frequency components and fewer high-frequency components compared to white noise. Pink noise sounds more balanced and less harsh than white noise, and it’s often used in audio engineering and acoustics for testing purposes.
Brown noise vs white noise
Brown noise, also known as “Brownian” or “red noise,” has a power spectral density that decreases as the frequency increases, specifically proportional to 1/f^2. This means that the energy in the lower frequencies is much higher than in the higher frequencies. Brown noise sounds deeper and more rumbling than both white and pink noise.
So, to sum it up, white noise has equal energy at each frequency, pink noise has equal energy per octave, and brown noise has a power spectral density that decreases as the frequency increases. These differences in frequency distribution result in distinct sound characteristics for each type of noise.
