decibel
DES-uh-bel
/ˈdes.ɪ.bel/
A logarithmic unit used to measure the intensity of a sound or the power level of an electrical signal.
Because it is logarithmic, an increase of 10 decibels represents a tenfold increase in sound energy.
The story behind the word. Coined in the 1920s by engineers at Bell Telephone Laboratories. They named the base unit 'Bel' after founder Alexander Graham Bell; a 'decibel' (dB) is one-tenth of a Bel, created to provide a convenient scale for human hearing range.
Word relationships
- volume level: 'Volume level' is an informal perceptual term, whereas 'decibel' is an exact quantitative logarithmic unit.
Commonly confused with
- hertz: Hertz measures sound frequency (cycles per second), whereas decibel measures sound intensity and volume.
Collocations
- decibel level
- peak decibels
- decibel rating
- decibel scale
Example sentences
- "Factory workers must wear ear protection when machinery noise exceeds eighty-five decibels." Occupational Safety
- "Engineers redesigned the jet engine turbine blades to reduce peak decibel levels during takeoff." Aviation
Memory hook
DECI (one-tenth) + BELL (Alexander Graham Bell) = DECIBEL, measuring phone and sound volume. DECIBELS count sound volume.
When not to use
Do not use as a direct measure of linear acoustic distance or wave velocity.
Fun facts
- A blue whale's call can reach 188 decibels underwater, making it louder than a jet engine at takeoff.
Related words
Also appears in
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