decibel

[ des-uh-bel, -buhl ]

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

decibel

/ 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

decibel

/ 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.

decibel

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

Word History and Origins

Origin of decibel¹

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

Example Sentences

The decibel level increased by several orders of magnitude when the video scoreboards displayed the image of Freeman with his son in his arms.

From Los Angeles Times

Over the last two weeks, players have done cartwheels, performed leaping body bumps and raised the decibels to helicopter-hovering levels.

From Los Angeles Times

Musgrove said there is a purpose behind those two words, and all the decibels that come with them.

From Los Angeles Times

Volume is measured in decibels, or units of sound pressure.

From Los Angeles Times

When Donald Trump delivers his acceptance speech on Thursday, the response from the crowd in Milwaukee will be even more deafening, the decibel level perhaps louder than a jet taking off from an aircraft carrier.

From Salon