Decibels
Unit is Bel, but because this is large, deci-Bels (1/10th Bel) are used), Symbol is dB.
Decibels are used in audio because they are a logarithmic measure of voltage, current or power, and correspond well to the response of the ear.
A 3dB change is half or double the power (0.707 or 1.414 times voltage or current respectively).
@BasicElectronics
