A noise exposure threshold value for hearing conservation
As part of a proposed EU directive for health and safety at work, a noise exposure threshold level of 75 decibels (A-weighted) over an 8-hour working day has been specified. This is stated to be the value below which continuous and/or repetitive exposure has no adverse effect on the health and safety of workers. This review considers the scientific background to the current international standard used to set the threshold level. Other literature data are reviewed, taking into account hearing loss due to the combination of natural ageing and exposure to noise. It is concluded that a threshold level of 75 dB(A) is overly conservative and that a daily noise exposure threshold level of 80 dB(A) can deliver suitable hearing protection.