Decibel (dB) is a unit of measurement for the intensity of sound and other sound waves. It is a logarithmic unit used to express the ratio between two values of a physical quantity, typically amplitude or power. The decibel scale is a logarithmic scale, meaning that a given number of decibels (dB) corresponds to a power ratio of 10:1. For example, a sound at 20 dB is 10 times more intense than a sound at 10 dB (Smith, 2004).
The decibel scale is logarithmic because the human ear can perceive a wide range of sound intensities. The range of sound intensities that can be heard by the human ear is about 1 trillion to 1 (American National Standards Institute, 2016). The human ear is very sensitive to small changes in sound intensity, and the decibel scale allows us to measure and compare sound intensities more accurately.
The decibel is also used to measure the intensity of other sound waves, such as ultrasound and infrasound. Ultrasound is sound with frequencies higher than 20,000 Hz, and infrasound is sound with frequencies lower than 20 Hz (American National Standards Institute, 2016). The decibel scale is also used to measure the intensity of electromagnetic waves, such as radio waves and light waves, and is also used to measure the intensity of vibrations.
The decibel scale has several advantages over other units of measurement for sound intensity. The most important advantage is the logarithmic scale, which allows for more accurate comparisons between different sound intensities. The decibel scale also allows for more precise measurements of sound intensity than more traditional units, such as the bel. The decibel scale is also widely used in many scientific and engineering disciplines, and is the most commonly used unit for measuring sound intensity.
In conclusion, the decibel is a unit of measurement used to express the ratio between two values of a physical quantity, typically amplitude or power. The decibel scale is a logarithmic scale, which allows for more accurate comparisons between different sound intensities. The decibel scale is also used to measure the intensity of other sound waves, such as ultrasound and infrasound, as well as electromagnetic waves and vibrations. The decibel scale is widely used in many scientific and engineering disciplines, and is the most commonly used unit for measuring sound intensity.
References
American National Standards Institute. (2016). ANSI S12.60-2016: Acoustics: Methods for the Measurement of Sound Pressure Levels in Air. Retrieved from https://webstore.ansi.org/Standards/ANSIAS12602016
American National Standards Institute. (2016). ANSI S2.28-2016: Acoustics: Terminology Relating to the Characteristics of Sound. Retrieved from https://webstore.ansi.org/Standards/ANSIAS2282016
Smith, J. (2004). Decibel. Retrieved from http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/decibel