DeciBel (dB)

The term dB (deciBel) and the dB scale are used world-wide for the measurement of sound levels. The deciBel scale is a logarithmic scale where a doubling of sound pressure corresponds to a 6 dB increase in level. 

It is important to realize that the term 'dB' can have different meanings and is not a fixed value like the volt or the meter etc. The value of a dB depends on the context in which it is used.