1 decibel | Definition of decibel

decibel

noun
deci·​bel | \ ˈde-sÉ™-ËŒbel How to pronounce decibel (audio) , -bÉ™l How to pronounce decibel (audio) \

Definition of decibel

1a : 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

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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.

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

Be aware of immediate noise: Any sounds above 85 decibels (dB) can permanently damage hearing. Houston Chronicle, "Expert: Follow 10 tips to preserve hearing health," 16 Aug. 2019 There are four bedrooms on board, all with improbably good closet space and their own bathrooms, the latter being the feature that garnered the highest decibels of admiration from our exploring party. Jo Rodgers, Condé Nast Traveler, "On the Slow Boat Through Burgundy: A Barge Trip in France," 3 July 2019 Artillery rounds created sustained noise levels above 140 decibels and were intense enough to split eardrums. Chuck Thompson, Popular Mechanics, "What You Need To Know Before Watching "They Shall Not Grow Old"," 28 Dec. 2018 The audience response is so high-decibel, her signature closing line is all but drowned out. Peter Marks, Washington Post, "Elizabethan," 21 Aug. 2019 It is known to be one of the loudest in all of FBS, reaching 132.8 decibels. Bobby Sullivan, SI.com, "The Greatest Stadiums in College Football History," 12 Aug. 2019 Others were below 90 decibels but still above the EPA's threshold. Evan Simko-bednarski, CNN, "Some kids say hand dryers hurt their ears. A Canadian girl conducted a study about it," 4 July 2019 In 1981, the FAA established DNL 65 decibels as the guideline at which federal funding is available for soundproofing, which can include new doors and windows for houses impacted by high jet noise levels. Mary Wisniewski, chicagotribune.com, "Long wait for FAA noise study raises questions: Quigley," 3 July 2019 While there are many factors taken into consideration, a home or neighborhood needs to meet at least these two criteria to qualify: Is the area impacted by noise that exceeds 66 decibels for at least an hour per day? Dixita Limbachia, Detroit Free Press, "Sound walls planned for I-75 in Oakland County: What we know," 17 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'decibel.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of decibel

1928, in the meaning defined at sense 1a

History and Etymology for decibel

International Scientific Vocabulary deci- + bel

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More Definitions for decibel

decibel

noun

English Language Learners Definition of decibel

technical : a unit for measuring how loud a sound is

decibel

noun
deci·​bel | \ ˈde-sÉ™-ËŒbel How to pronounce decibel (audio) , -bÉ™l\

Kids Definition of decibel

: a unit for measuring the loudness of sounds

decibel

noun
deci·​bel | \ ˈdes-É™-bÉ™l How to pronounce decibel (audio) , -ËŒbel How to pronounce decibel (audio) \

Medical Definition of decibel

1a : 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

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