For the purposes of this Directive, the physical parameters used as risk predictors are defined as follows:
peak sound pressure (ppeak): maximum value of the ‘C’-frequency weighted instantaneous noise pressure;
daily noise exposure level (LEX,8h) (dB(A) re. 20 μPa): time-weighted average of the noise exposure levels for a nominal eight-hour working day as defined by international standard ISO 1999: 1990, point 3.6. It covers all noises present at work, including impulsive noise;
weekly noise exposure level (LEX,8h ): time-weighted average of the daily noise exposure levels for a nominal week of five eight-hour working days as defined by international standard ISO 1999:1990, point 3.6 (note 2).