Handicap Equations
Presbycusis used to Project Hearing Loss
nIt is assumed with all of the calculators that hearing loss due to noise and presbycusis are additive. 
 
nISO 1999 compression factor is applied when projecting audiometric data.
  
nHearing Loss = ARL + NIL - (ARL * NIL)/120
n   ARL:  Age Related Loss,  NIL:  Noise Induced Loss