decibel

noun

deci·​bel ˈde-sə-ˌbel  -bəl 

1

a

: a unit for expressing the ratio of two amounts of electric or 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 analogous acoustic 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 the average least perceptible sound to about 130 for the average pain level

3

: degree of loudness

also : extremely loud sound

—usually used in plural

Did you know?

The unit for measuring the relative intensities of sound is called a decibel. Because the decibel scale is logarithmic, a sound with an intensity that is twice that of a reference sound corresponds to an increase of little more than 3 decibels. In common practice, the reference point of 0 decibel is set at the intensity of the least perceptible sound, the threshold of hearing. On such a scale a 10-decibel sound is 10 times the intensity of the reference sound; a 20-decibel sound is 100 times the reference intensity, and so on. Normal conversation is usually around 60 decibels, an electric saw around 100 decibels, and amplified rock music around 120 decibels.

Synonyms

• babel
• blare
• bluster
• bowwow
• brawl
• bruit [archaic]
• cacophony
• chatter
• clamor
• clangor
• din
• discordance
• katzenjammer
• noise
• racket
• rattle
• roar

Examples of decibel in a Sentence

a rock concert blasting music at 110 decibels

the crowd decibels increased dramatically as the horses neared the finish line

Recent Examples on the Web

The decibel level inside a human body can exceed that of a vacuum cleaner, and much of the roar comes from the blood. —Blake Nelson, The Mercury News, 13 Oct. 2024

Loop’s Experience line is specially made for concerts by dampening the decibels without sacrificing the performer’s sound quality. —Jessica Comstock, Better Homes & Gardens, 18 Sep. 2024

The case stemmed from noise citations written by Hood County constable John Shirley, who has recorded dozens of readings the past few months over 85 decibels, the state’s threshold for which noise is considered unreasonable. —Noah Alcala Bach, Fort Worth Star-Telegram, 11 July 2024

Over the course of 2024, Shirley has recorded a noise above 85 decibels coming from the plant more than 35 times. —By Andrew R Chow/granbury, Texas, TIME, 8 July 2024

Word History

Etymology

International Scientific Vocabulary deci- + bel

First Known Use

1928, in the meaning defined at sense 1a

Kids Definition

decibel

noun

deci·​bel ˈdes-ə-ˌbel 

-bəl

: a unit for measuring the relative loudness of sounds

—abbreviation dB

Medical Definition

decibel

noun

deci·​bel ˈdes-ə-bəl  -ˌbel 

1

a

: a unit for expressing the ratio of two amounts of electric or 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 analogous acoustic 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 the average least perceptible sound to about 130 for the average pain level