decibel


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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.

dec·i·bel (dB, db),

(des'i-bel), Avoid the mispronunciation des'i-b'l.
One tenth of a bel; unit for expressing the relative intensity of sound on a logarithmic scale.
[L. decimus, tenth, + bel]

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 (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.

dec·i·bel

(dB) (des'i-bĕl)
One tenth of a bel; unit for expressing the relative loudness of sound on a logarithmic scale.
[L. decimus, tenth, + bel]

decibel

A logarithmic unit of comparison between a standard power level and an observed level. The decibel is not a unit of sound intensity but is widely used to compare a noise level with a very low standard reference level near the limit of audibility, and to compare electrical power levels. A tenth of a bel.

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)

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.

dec·i·bel

(dB) (des'i-bĕl)
One tenth of a bel.
[L. decimus, tenth, + bel]

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.
References in periodicals archive ?
People with moderate deafness may have difficulty following speech without a hearing aid, and find the quietest sounds they can hear are 40 to 69 decibels.
In a study published by the Naval Health Research Center, scientists found that 24-hour exposure to low-frequency sonar at only 77 decibels produced "adverse effects on health, performance, and morale" on human sailors.
The decibel unit, though, still has strong supporters.
Long or repeated exposure to sounds at or above 85 decibels can cause hearing loss," according to the NIH, which includes noises from motorcycles, firecrackers and small firearms, which create noise in the 120- to 150-decibel range.
The World Health Organisation says that listening to earphones at 85 decibels or more for over an hour at a time can damage hearing.
The organisers, Big Day Out, have been given the go-ahead by Perth and Kinross Council to let bands play their hits at 140 decibels.
The district tested the alarms' decibel level, and although it is below the industry standard - it can't be higher than 120, similar to an ambulance siren - officials said they want to properly address the concerns of the more than 100 teachers on campus.
Decibel meters, often employed in a bid to settle noise disputes, were used.
More than 80 events in venues across the region go to make up the Decibel Xpo festival, part of the Arts Council's national Decibel initiative.
Under the new rule, the criteria will record 10-decibel shifts from the employee's initial hearing test when they also result in an overall hearing level of 25 decibels.