What is Pink Noise and What Does It Do?

Author: Tyler Cox

Most of us are familiar with the term “white noise,” which is often used to describe the static between stations on a radio, the sound of a rainstorm, or even a boring lecture. There are even sound machines on the market that purport to help us fall asleep by playing white noise.
 

What many of us don’t know is that noise comes in a kaleidoscope of colors. Along with white noise, there are various colors, including brown noise, green noise, and blue noise. When it comes to audio equipment, one of the most important colors in the spectrum is pink noise.

 

The Difference Between White Noise and Pink Noise

To start, let’s define white noise and look at the relationship between white noise vs. pink noise. Simply put, white noise is random noise that has the same intensity across all frequencies of the audio spectrum, between 20 and 20,000 Hz. It’s analogous to white light, which contains all the wavelengths of the visible spectrum. Many interpret white noise as a hissing sound. 

 

Pink noise, on the other hand, is composed of equal energy in all octaves (halving or doubling) of frequency. Although the concept might be difficult to grasp for non-scientists, the primary difference between pink and white noise is that the power is constant across the spectrum with white noise. Still, with pink noise, the difference in power becomes smaller as the numbers get bigger. As a result, with pink noise, higher-pitched sounds are softer than lower-pitched sounds.

 

Pink noise is often found in biological systems such as heartbeats, the sound of rustling leaves, and even our thought patterns. Our ears can quickly tell the difference between white noise and pink noise. In fact, those devices that are billed as having the ability to help us sleep better are often called white noise generators but are actually pink noise generators.


Using Pink Noise For Audio Tuning

Because many musical and natural sounds have spectra that decrease in intensity at high frequencies, audio engineers often use pink noise to test the frequency response of communication systems. For example, in a conference room, frequency response can be affected by factors including the shape of the room, the type of furniture, and the carpeting on the floor. Communication systems that don’t have a flat frequency response in a particular room can be adjusted or “tuned” for optimum audio quality.
 

ADECIA AUTO-TUNING

 



Although an audio engineer can spend hours or days in a conference room with a digital audio tuner, measuring its acoustic qualities and testing microphones and speakers' placement, most organizations don’t have the time or resources for such a task. That’s why communication systems such as Yamaha UC’s ADECIA ceiling microphone system incorporate pink noise generators. ADECIA’s setup wizard automatically detects connected speakers and microphones and offers the option to Execute Automatic Audio Tuning, playing pink noise through the speakers while listening through the microphone array. The wizard makes tuning adjustments during the process, taking into account the location of speakers and microphones, the room’s reverberation characteristics, and echo responses, matching the system to the environment within minutes.

 

And if the layout of the room changes in any way, it’s easy to re-tune the system to match the new environment.

For information from Yamaha UC on conference room audio, check out this Guide to Conference Room Microphone Setup. To learn about the best ways to set up your conference room read Conference Room Layouts for Different Meeting Situations. For additional help, contact the experts at Yamaha UC.