The decibel (dB) is a unit used to express the ratio of two values of a physical quantity, often power or intensity. One decibel is one-tenth of one bel, a unit name named in honor of Alexander Graham Bell. This unit ‘bel’ is seldom used.
A decibel meter is used for acoustic measurements. Sound traveling in acoustic means that the sound is traveling through the air. This instrument is usually a small device with a microphone that measures noise meter. In acoustic, a diaphragm is a transducer intended to interconvert mechanical vibrations to sounds, or vice versa. The diaphragm present in the microphone reacts to the changes in air pressure due to sound waves.
This is another reason why this instrument is also referred to as a Sound Pressure Level (spl meter). In the diaphragm movement, the sound pressure deviation is converted into an electrical signal (V).
When a constant pressure is applied, a microphone can be traced by the voltage produced, called as the microphone sensitivity. Decibel meter uses the sensitivity of the microphone and converts the electrical signal accurately to sound pressure, and show the resulting level of sound pressure (decibels dB).
This instrument is usually used to measure noise and serves as a level meter. If human beings are exposed to loud noises for a brief period, it doesn’t cause much harm, but continuous exposure can do physical damage like eardrums damage.
Sound level meters are mostly used in noise pollution studies to analyze the quantification of various kinds of noise. Thus, this device helps to measure the intensity of the sound, which can measure the decibel of the sound, so that one can take effective measures to reduce it.