decibel

American  

[des-uh-bel, -buhl] / ˈdɛs əˌbɛl, -bəl /

noun

Physics.

1. a unit used to express the intensity of a sound wave, equal to 20 times the common logarithm of the ratio of the pressure produced by the sound wave to a reference pressure, usually 0.0002 microbar.

2. a unit of power ratio, the number of units being equal to a constant times the logarithm to the base 10 of the intensities of two sources.

3. a unit used to compare two voltages or currents, equal to 20 times the common logarithm of the ratio of the voltages or currents measured across equal resistances. dB, db

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decibel British  

/ ˈdɛsɪˌbɛl /

noun

1. a unit for comparing two currents, voltages, or power levels, equal to one tenth of a bel

2. a similar unit for measuring the intensity of a sound. It is equal to ten times the logarithm to the base ten of the ratio of the intensity of the sound to be measured to the intensity of some reference sound, usually the lowest audible note of the same frequency

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decibel Scientific  

/ dĕs′ə-bəl /

1. 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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decibel Cultural  

1. A unit of measurement of the volume of sounds.

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Etymology

Origin of decibel

First recorded in 1925–30; deci- + bel ¹

Example Sentences

The numbers that were perhaps most telling though were on the Twickenham decibel meter, showing the love for a team that has not always felt it.

From BBC

A “Go Big Red!” chant filled the air before the coin toss, the decibel level increasing when Nebraska scored on its opening drive.

From Los Angeles Times

It would eliminate the possibility of the Dodgers playing for their lives on Saturday, amid the deafening decibels of Citizens Bank Park.

From Los Angeles Times

Tense discussions of life-altering events are matched by the diegetic decibels of smooth jazz or string symphonies.

From Salon

Another new rule: Sound must be 85 decibels or below during marches, which are not allowed to disrupt classes and programs or block walkways.

From Los Angeles Times