A common measure of sound intensity that is 1 tenth of a bel on the logarithmic intensity scale. It is defined as dB = 10 * log10(P 1/P 2), where P1 and P2 are the relative powers of the sound
A decibel is a unit of measurement which is used to indicate how loud a sound is. Continuous exposure to sound above 80 decibels could be harmful. a unit for measuring the loudness of sound (deci- + bel unit of sound power (20-21 centuries), from Alexander Graham Bell (1847-1922), US inventor). Unit for measuring the relative intensities of sounds or the relative amounts of acoustic or electric power. Because it requires about a tenfold increase in power for a sound to register twice as loud to the human ear, a logarithmic scale is useful for comparing sound intensity. Thus, the threshold of human hearing (absolute silence) is assigned the value of 0 dB and each increase of 10 dB corresponds to a tenfold increase in intensity and a doubling in loudness. The "threshold of pain" for intensity varies from 120 to 130 dB among different individuals. A related unit is the bel = 10dB
The standard unit for expressing transmission gain or loss and relative power ratios The decibel is one tenth the size of a Bel, which is too large a unit for convenient use Both units are expressed in terms of logarithm to the base 10 of a power ratio used primarily for attenuation and crosstalk measurements in telecommunications
A unit for measuring the relative strength of a signal Usually expressed as the logarithmic ratio of the strength of a transmitted signal to the strength of the original signal
A unit to express differences in power In acoustics, equal to ten times the logarithm of the ratio of one sound and lower-intensity reference sound One decibel indicates a difference of about 26% and is about the smallest change the ear can detect The dB level is a logarithm quantity; the maximum normal level is approximately 120dB
A decibel is one-tenth of a bel and is equal to 10 times the logarithm of the power ratio, 20 times the log of the voltage ratio, or 20 times the log of the current ratio Decibels are also used to express acoustic power, such as the apparent level of a sound The decibel can express an actual level only when comparing with some definite reference level that is assumed to be zero dB
A dimensionless unit for expressing the ratio of two values of power, current, or voltage The number of decibels being equal to: dB = 10 log P2 / P1 = 20 log V2 / V1 = 20 log I2 / I1 Normally, used for expressing transmission gains, losses, levels, and similar quantities
The unit by which amplitude is measured Decibel measurements occur along a logarithmic scale in which each 10 dB increase represents a tenfold increase in signal amplitude, while each 10 dB reduction represents a tenfold reduction The original unit of measurement was the Bel, a ten times larger measurement (ie, one Bel = ten dB) As electronic equipment improved, however, its one-tenth-size relative, the decibel, came to be the standard unit The dB scale is useful in measuring changes in systems which our nervous systems perceive in logarithmic ways, such as sound The most common use of the decibel is in measuring sound pressure level
The standard unit used to express gain or loss of optical power A standard logarithmic unit for the ratio of two powers, voltages or currents In fiber optics, the ratio is power
snv A unit to express sound pressure level The decibel is the unit of level when the base of the logarithm is the tenth root of ten, and the quantities concerned are proportional to power The dB has meaning only when the referenced quantity is known The internationally accepted reference pressure in acoustics is 20 micropascals (µPa) which corresponds to 0 dB See "Sound pressure level " [MIL-HDBK-1908B]
A unit for comparing two currents, voltages or power levels based on a logarithmic scale It is used particularly for expressing the difference between very large and very small values (expression: R = 10*log10(r), where r is the linear ratio and R is the ratio in dB)
One-tenth of a bel It is equal to 10 times the logarithm of the power ratio, 20 times the log of the voltage ratio, or 20 times the log of the current ratio One decibel is the amount by which the pressure of a pure sine wave of sound must be varied in order for the change to be detected by the average human ear The decibel can express an actual level only when comparing with some definite reference level that is assumed to zero dB
a common measure of sound intensity that is 1 tenth of a bel on the logarithmic intensity scale. It is defined as dB = 10 * log{10}(P {1}/P {2}), where P{1} and P{2} are the relative powers of the sound