White Noise and Pink Noise: Here Are the Differences

In the acoustic field, people often wonder what the difference between white noise and pink noise is. Sound masking systems are often described as “white noise machines” or “pink noise speaker systems.” In reality, roughly speaking, it can be stated that they are a combination of both. White noise has the same sound intensity at all frequencies, while pink noise decreases in intensity as frequency increases. This aspect should be considered positive, as high frequencies often sound “hissing” to the human ear and can cause discomfort or distractions throughout the day. As we were able to understand in the previous paragraph, white noise and pink noise each possess certain characteristics and are used to counteract the sound effect that would otherwise be created in highly frequented environments or those characterized by large spaces. Often, therefore, it proves useful to use a combination of them rather than opting for solutions in which only one of the two is present at the expense of the other. Advanced sound masking systems indeed combine white noise and pink spectra in a curve that has been empirically proven, which allows for better attenuation of unwanted noise. The spectrum is adjusted in the field based on the thickness of the acoustic ceiling panels, which block high frequencies more easily.

White noise systems

White noise, at all frequencies, has the same decibel level; it can also be described as static noise. However, this very characteristic can be annoying to the human ear which, precisely, is more sensitive to sounds with high tones. A noise at 50dB but with a frequency of 125 Hz, for example, is much less annoying than a sound of the same decibels, but with a frequency of 2000 Hz.

How should white noise be?

Generally, white noise should be sufficiently loud to cover other unwanted sounds, whether in a residence or a workspace. This minimum level does not allow it to be annoying, but at the same time prevents potential distractions or disturbances from sounds present in the same environment. In practice, what has just been described translates, for example, into setting the white noise level at approximately 43-45 dBA (A-weighted Decibels, which measure the variation in sound intensity according to the greater sensitivity of the human ear) in closed offices and 45-48 dBA in open offices. It should be noted, however, that these levels may vary based on the different circumstances that arise from time to time. In areas where there are significant noise problems, the level can be raised up to 50 dBA; beyond this threshold, the effect begins to fade, as even white noise would become disturbing.

Pink Noise and White Noise: conclusions

Overall, white noise and pink noise are both sound masking spectra used to cover unwanted sounds. White noise is static, and is the same at all frequencies – high and low. Conversely, pink noise drops at high frequencies so as not to annoy individuals present in a particular space or environment. Sound masking systems use a mixture of these spectra based on the ceiling panel and other factors in the space to determine what is best to tune and balance the system.