decibel

de·ci·bel   (děs'ə-bəl, -běl')    n.   Abbr. dB A unit used to express relative difference in power or intensity, usually between two acoustic or electric signals, equal to ten times the common logarithm of the ratio of the two levels. [deci- + bel.]

Main Entry: deci·bel
Pronunciation: 'des-&-b&l, -"bel
Function: noun
1 a : a unit for expressing the ratio of two amounts of electricor acoustic signal power equal to 10 times the common logarithm of this ratio b : a unit for expressing the ratio of the magnitudes of two electric voltages or currents or analogousacoustic quantities equal to 20 times the common logarithm of the voltage or current ratio
2 : a unit for expressing the relative intensity of sounds on a scale from zero for theaverage least perceptible sound to about 130 for the average pain level

decibel de·ci·bel (děs'ə-bəl, -běl')
n.
Abbr. dB
A unit used to express relative difference in power or intensity, usually between two acoustic or electric signals, equal to ten times the common logarithm of the ratio of the two levels.

decibel   (děs'ə-bəl)  Pronunciation Key  A unit used to measure the power of a signal, such as an electrical signal or sound, relative to some reference level. An increase of ten decibels in the power of a signal is equivalent to increasing its power by a factor of ten. As a measure of sound intensity, a zero-decibel reference is stipulated to be the lowest level audible to the human ear; the speaking voice of most people ranges from 45 to 75 decibels.