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

Irvin said the decibel limits are based off of recommendations from the Centers of Disease Control and Prevention. —Neal Earley, arkansasonline.com, 11 Apr. 2024

The underwater call of the sperm whale, the earth’s loudest, registers at 230 decibels. —Clare Mulroy, USA TODAY, 3 Apr. 2024

In fact, listening at 100 decibels for just 15 minutes (about the sound level of a bulldozer) delivers the same hit to your hearing as seven or eight hours at 85 decibels. —Amy Paturel, WIRED, 24 Mar. 2024

Songs by Spanish and Mexican pop artists play at high decibels, making swaying in one’s seat easy, but conversations slightly more challenging. —The Arizona Republic, 26 Feb. 2024

Doorbell cameras and noise decibel monitors will still be allowed on Airbnb properties, but other outdoor cameras must be disclosed, including their location, before guests book the property. —Chris Morris, Fortune, 12 Mar. 2024

Hosts will also be required to disclose the presence of noise decibel monitors on the property in the listing. —Esme Mazzeo, Peoplemag, 11 Mar. 2024

The company is also revising its rules about outdoor security cameras and other devices, like noise decibel monitors. —Rob Wile, NBC News, 11 Mar. 2024

However, some small animals can make incredibly loud noises for their size, including the snapping shrimp, which use their claws to make popping sounds that measure up to 250 decibels, the release adds. —Jack Guy, CNN, 27 Feb. 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