Noise, in the context of industrial noise, is hazardous to a persons hearing because of its loud intensity through repeated long-term exposure. In order for Noise to cause Hearing impairment for the worker, the noise has to be close enough, loud enough and the listener has to be exposed for long enough. These factors have been taken into account by the governing occupational health and safety organizations as they determine the unsafe noise exposure levels and durations for their respective industries.