<p><strong>Noun:</strong></p><ul><li>A unit used to express the intensity of a sound wave, equal to 20 times the common logarithm of the ratio of the pressure produced by the sound wave to a reference pressure, usually 0.0002 microbar.</li><li>A unit of power ratio, the number of units being equal to a constant times the logarithm to the base 10 of the intensities of two sources.</li><li>A unit used to compare two voltages or currents, equal to 20 times the common logarithm of the ratio of the voltages or currents measured across equal resistances.</li></ul><p><strong>End of Response</strong></p>