Decibel definition

dĕsə-bəl, -bĕl
(acoustics) A numerical expression of the relative loudness of a sound: the difference in decibels between two sounds is ten times the common logarithm of the ratio of their power levels.
noun
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(electronics, radio) A numerical expression of the relative differences in power levels of electrical signals equal to ten times the common logarithm of the ratio of the two signal powers Sometimes an absolute reference is used in the power ratio (10-16 watt per sq cm in acoustics, one milliwatt in electronics and radio)
noun
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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.
noun
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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.
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The definition of a decibel is a degree of loudness, or is a unit used to measure how powerful or loud a sound or signal is using a logarithmic formula.

When you turn your iPod up as loud as it can possibly go, this is an example of when you listen to your music at the highest decibel.

noun
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See dB.
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A common measure of sound intensity that is one 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.
noun
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Other Word Forms

Noun

Singular:
decibel
Plural:
decibels

Origin of decibel

  • deci– bel

    From American Heritage Dictionary of the English Language, 5th Edition