decibel
nounUK /ˈdes.ɪ.bel/
US /ˈdes.ə.bel/
A decibel is a unit used to measure how loud a sound is.
The music at the concert reached over 100 decibels.
OTHER MEANINGS
2. A unit used to express the intensity of an electrical or other signal relative to a reference level.
The amplifier's gain was set to 20 decibels.
3. A small, barely noticeable amount of something.
She didn't lower her voice a decibel during the argument.
4. A logarithmic unit used in physics and engineering to compare two power or intensity levels.
The signal-to-noise ratio improved by 3 decibels.