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 dBUnderwater Acoustic Impacts of COVID-19Glossary: critical ratioAmplitude (Intensity)Tutorial: Intensity or LoudnessWhat units are used to measure sound? Derek Sutcliffe2017-02-26T20:09:57-05:00