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Exploring the Frequencies Below Brown Noise

May 17, 2024

While many people are familiar with white and pink noiseWhile many people are familiar with white and pink noise, there is another lesser-known type of noise that lies at a further lower end of the frequency spectrum: brown noise. Named after its discoverer, Robert Brown, brown noise is characterized by its deep, rumbling sounds and its power density, which decreases by 6 decibels per octave. It has been known to aid in sleep and relaxation and is also used in the fields of audio engineering and acoustics.


However, what if we venture further below the spectrum of brown noise? Are there any frequencies that lie even lower? In this article, we'll explore the world of infrasound and how it compares to brown noise.


Infrasound refers to sound waves with frequencies below 20 Hertz, which are typically considered inaudible to the human ear. Although humans cannot consciously perceive these low-frequency sounds, they can still have physiological effects on the body. Infrasound can be generated by natural phenomena such as earthquakes, volcanic activity, and animal vocalizations. It has also been documented that exposure to infrasound can induce feelings of uneasiness, anxiety, and even fear in some people.


Despite these intriguing characteristics of infrasound, it is not a type of noise that should be compared to brown noise. Rather than existing as a type of colored noiseRather than existing as a type of colored noise, infrasound is a specific range of sounds that extends across multiple colors of noise. Brown noise, on the other hand, is a specific type of noise characterized by its unique power density distribution and frequency spectrum.


In conclusion, while there may not be a specific type of noise that is lower than brown noise, the exploration of infrasound reveals a fascinating world of auditory phenomena that lies just beyond the realm of human hearing. Understanding the nature of these low-frequency sounds can help us better comprehend the mechanisms of sound perception and inform the development of innovative applications in fields such as environmental monitoring, geophysics, and even animal behavior research.


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