Handicap Equations
Presbycusis used to Mitigate Damages

nThe percentage of handicap due to presbycusis is often determined by ISO-1999 Annex A (Robinson Sutton's Data).  It is assumed that presbycusis and noise trauma are additive but one can argue in severe hearing losses that this is not true.  However, legally this is a mute point.  Since, either the two are additive and the percentage of presbycusis is predicted by Robinson Sutton's Equations or if they are not additive then some of the noise trauma prevented some presbycusis from taking place, or visa versa.  Thus, this percentage of noise trauma caused no harm and therefore would still not be compensatible.