Modeling the interactions between noise exposure and other variables

The interaction of noise exposure with other variables is reviewed. For the case of the interaction of noise with other variables that produce behavioral threshold shifts, the application of a newly developed model is described and demonstrated. This model, referred to as the modified power-law model, provides an accurate prediction of the combined effects of two threshold-elevating factors. The model accounts for the interaction of post-exposure threshold shift with pre-exposure hearing loss, whether the hearing loss was a pre-existing permanent loss or a pre-existing temporary loss. The model's application is demonstrated for multiple exposures to steady-state noise in which each exposure lasts as short as 12 min or as long as 6 h. Finally, implications of the model's application to the interaction of noise with other ototraumatic agents are reviewed.