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

Then, the noise levels of both the high and low settings were recorded using a decibel reader. —Alida Nugent, Better Homes & Gardens, 17 Nov. 2023

Because the gas must exit somehow, the frequency and volume (metric and decibel) of flatulence increases. —Kim Tingley, New York Times, 12 Nov. 2023

The sound from the crowd registered a whopping 14.2 decibels, which is louder than an airplane during take off. —Chantz Martin, Fox News, 18 Oct. 2023

While most mulchers run at around 65 decibels, Ryobi’s mulcher operates at 57 decibels. —Tony Carrick, Popular Mechanics, 1 Sep. 2023

Even lower-level sounds – around 85 decibels – can injure the ear if heard for extended periods of time. —Cory Portnuff, Discover Magazine, 29 Sep. 2023

Or, at least, that’s what Republicans were told, ad nauseam and at a deafening decibel, by elements of the Republican coalition who resented conventional conservative foreign-policy prescriptions. —Noah Rothman, National Review, 24 Aug. 2023

During testing, this space heater did register a few decibels louder than comparable heaters of the same size. —Katie Begley, Peoplemag, 24 Oct. 2023

Most produce a noise level in the mid-60 decibels (similar to an air conditioner or washing machine), compared with 75 to 100 decibels for a portable unit. —Laura Daily, Washington Post, 29 Aug. 2023

See More

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