Presbycusis
tNIOSH does NOT recommend accounting for presbycusis when looking for Medical Causation of a progressive hearing loss.   If a worker has a progressive hearing loss it is assumed to be due to noise trauma and corrective measures should be taken.
    
tHowever, estimation of presbycusis is used for compensation purposes.  The test for compensation is whether the hearing loss is medically more likely than not caused by noise exposure.