It is a term used in acoustics. It is a fraction of the unit of measure of the intensity or sound power (tenth), called bel Bel. Submultiple equivalent to tenth Bel. Its symbol is dB, Bel and Bel is B. As sound intensity or acoustic are so broad is more customary use measurements in decibels as well other than the unit. Measurements of noise pollution is in decibels (dB).
