Assessing occupational hearing loss: beyond noise exposures.

In recent years, findings that exposure to industrial chemicals may affect hearing and interact with noise brought to light a risk that had not been given substantial attention previously. The need for research becomes clear when the magnitude of the population of workers exposed to noise and chemicals and the number of potentially hazardous chemicals found in work environments are taken into consideration. The need for research is this area is further heightened by the fact that there are no guidelines or standards for combined exposures of chemical and physical agents. The present paper reviews the effects of combined exposures to chemicals and noise on hearing and examines study designs, hearing assessment alternatives, and strategies for the analysis of combined effects.