Decibel
Water
A unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 130 for the average level at which sound causes pain to humans.
Storage
The unit of measure used to indicate relative changes in signal intensity or sound volume. The actual expression for calculating the difference in decibels between signal A and signal B is:
decibel (dB) = 20·logbase10 (signal A amplitude/signal B amplitude)
+6 dB represents a doubling of the signal or a 100% increase
+5 dB represents a 78% increase
+4 dB represents a 58% increase
+3 dB represents a 41% increase
+2 dB represents a 26% increase
+1 dB represents a 12% increase
+0 dB represents no change-signals are equal
-1 dB represents a 11% decrease
-2 dB represents a 21% decrease
-3 dB represents a 29% decrease
-4 dB represents a 37% decrease
-5 dB represents a 44% decrease
-6 dB represents a halving of the signal or a 50% decrease
Telecommunications
See dB.