decibel /dec·i·bel/ (des´ĭ-bel) a unit used to express the ratio of two powers, usually electric or acoustic powers, equal to one-tenth of a bel; one decibel equals approximately the smallest difference in acoustic power the human ear can detect.
Decibel
decibel (dB)
decibel [des´ĭ-bel]
de·ci·bel (d s  -bl, -bl )n. Abbr. dB A unit used to express relative difference in power or intensity, usually between two acoustic or electric signals, equal to ten times the common logarithm of the ratio of the two levels. |
Decibel
A unit of measure for expressing the loudness of a sound. Normal speech is typically spoken in the range of about 20-50 decibels.
Mentioned in: Audiometry, Hearing Loss
decibel (dB)
[des′əbəl]
Etymology: L, decimus, one tenth, bel, Alexander G. Bell, Canadian inventor, 1847-1922
a unit of measure of the intensity of sound. A decibel is one tenth of 1 bel (B); an increase of 1 B is perceived as a 10-fold increase in loudness, based on a sound-pressure reference level of 0.0002 dyne/cm2, or 20 micropascals.
decibel [des´ĭ-bel]
a unit of relative power intensity equal to one tenth of a bel, used for electric or acoustic power measurements; one decibel equals approximately the smallest difference in acoustic power the human ear can detect and an increase of 10 decibels approximately doubles the loudness of a sound. Abbreviated dB or db.
Examples of decibel levels in everyday situations. From Frazier et al., 1996.
decibel (des´ibel),
n a logarithmic ratio unit that indicates by what proportion one intensity level differs from another.
decibel
a unit used to express the ratio of two powers, usually electric or acoustic powers, equal to one-tenth of a bel; one decibel equals approximately the smallest difference in acoustic power the human ear can detect. Abbreviated dB or db. See also bel.
decibel (dB)
1. Unit used for the measurement of the intensity of a sound. 2. Light intensities are often presented on a logarithmic (rather than linear) scale. This is done, in particular, to abbreviate large numbers. Moreover, it has become common, especially in perimetry, to use decibels rather than log units. A decibel scale is a logarithmic scale where 10 decibels are equal to 1 log unit; 20 decibels, to 2 log units, etc. In perimetry, decibels are used to indicate the attenuation of brightness of the stimulus. Thus, a 20 dB stimulus is equal to one-tenth the brightness of a 10 dB stimulus.
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