The general name for the level of the amount of noise exposure that an operator is subjected to measured at the workplace. Limits vary according to various national and international Health and Safety regulations for the amount of exposure that is considered allowable for an operator without hearing protection. Typical limit values are an equivalent steady level of 85 or 90 'A' weighted dB for an 8-hour working day. This is also known as the LEP,d or the Lex8hr.