The supervising national bodies The Norwegian Labour Inspection Authority and the Petroleum Safety Authority Norway regard noise exposure as a considerable problem, and want more knowledge on this area in order to improve supervision.

It is challenging to differentiate between work-related and age-related loss of hearing. New research suggests that hearing loss due to age is considerable, compared to hearing loss due to occupational exposure to noise. There are great individual variations. Since noise induced hearing loss is such a small part, diagnosing NIHL is difficult.

If one use The Norwegian Labour Inspection Authority guidelines for registering hearing loss as noise-related, there is a considerable risk for overdiagnosis. The goal of this project is to do a systematic literature review, the basis of this review will result in a report on the knowledge status in Norway as of 2013 on this field.