Decibel Range

Decibel Range

A decibel (dB) is a unit of measurement for sound. A-weighted decibels, abbreviated dBA, are an expression of the relative loudness of sounds in air which is perceived by our ears. It is a unit of measurement used to express the ratio of value of power or filed quantity to another, on a logarithmic scale. This power is called the power level or field level. It can be used to change is value or absolute value, which varies.

The normal conversation is about 60 dB, a lawn mower is about 90 dB, and a loud rock concert is about 120 dB. Generally any sound above 85 are harmful, and it depends on how long one is exposed to the sound and if the usage of hearing protection like,  earplugs or earmuffs are being used. (NIOSH) - The National Institute of Occupational Safety,states that for a 115 dB sound, the limit is 28 seconds of exposure. The safe noise level of 70 dB over 24 hours will damage ones hearing, says the Environmental Protection Agency (EPA).

Today. the decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory. In electronics, the gains of amplifiers, attenuation of signals, and signal-to-noise ratios are often expressed in decibels. The measurement of power began in the early 20th century in the Bell System in the US, which is named in honor of Alexander Graham Bell.