Apparent Loudness 2 : Measurement in decibels of sound pressure measured against the threshold of hearing, being 0 decibels. The pain threshold is 120 decibels and an increase of 3 decibels is perceived as doubling in loudness
EDP - The Right Approach, Health & Safety Terms and Abbreviations, Health, Safety & Environment Consultants Ltd, UK 2010. http://www.edp-uk.com/glossary.htm, (Envir Hlth and Sfty - Brit) {50}
EDP - The Right Approach, Health & Safety Terms and Abbreviations, London, UK 2014. http://www.edp-uk.com/Resources/Health-Safety-Term s-and-Abbreviations, (Envir Hlth and Sfty - Brit) {768}