Decibel: Learn what decibel is

Learn what decibel is, how to calculate it, and how to measure sound with a decibel meter. Explore the decibel scale and chart with examples of different sound sources and their dB levels. Definition and examples The decibel (dB) is a logarithmic unit used to measure sound level. It is also widely used in electronics, signals and communication. The dB is a logarithmic way of describing a ratio. The ratio may be power, sound pressure, voltage or intensity or several other things. Later on we relate dB to the phon and to the sone, which measures loudness. But first, to get a taste for logarithmic expressions, let's look at some numbers. (If you have forgotten, go to What is a ... Decibel (Symbol: dB) is a logarithmic unit that indicates ratio or gain. Decibel is used to indicate the level of acoustic waves and electronic signals. The logarithmic scale can describe very big or very small numbers with shorter notation. The decibel may be defined by the statement that two amounts of power differ by 1 decibel when they are in the ratio of 10 0.1 and any two amounts of power differ by N decibels when they are in the ratio of 10 N(0.1).