Decibel (dB) 02 : A dimensionless unit used to compare the magnitudes of sound pressure squared. It is used as a measure of the level of sound above a reference value being approximately the quietest sound that a person can hear
Ministry of Business, Innovation and Employment, Glossary of terms and acronyms, Wellington, New Zealand 2010. http://wwwsosh.govt.nz/resources/glossary-u.shtml, (Occupn Hlth and Sfty - Brit) {530}