decibel decibela relative unit used to describe sound intensities. Written as dB. See Advanced Topic: Introduction to Decibels.Related Articles: Glossary: source levelGlossary: phonGlossary: sound exposure level (SEL)Glossary: sound levelGlossary: underwater dBAmplitude (Intensity)Sonar Equation Example: Active SonarDOSITS VideosHow does sound in air differ from sound in water?Introduction to Decibels Derek Sutcliffe2017-02-26T20:09:57-05:00