title: Estimating noise-induced permanent threshold shift from audiometric shape: the ISO-1999 model.
abstract: OBJECTIVE
  To describe the relation between audiometric shape and noise-induced permanent threshold shift averaged across the speech frequencies (N5123).
  
  
  METHODS
  Using an international standard (ISO-1999), 270 audiograms were created, representing both sexes and a variety of ages, exposure levels, and percentiles. Bulge depth (BD) was defined as the difference between pure-tone average for 2, 3, and 4 kHz and PTA for 1 and 6 kHz.
  
  
  RESULTS
  N5123 was well-predicted by quadratic functions of BD, which accounted for 72 to 95% of the variance in N5123.
  
  
  CONCLUSIONS
  Estimates of N5123, based on BD, can be helpful in medical-legal diagnosis and allocation of hearing loss.
authors.affiliation: University of California-Davis Medical Center and Dobie Associates, Sacramento, California, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Dobie
mesh_terms: D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D013067:Speech Perception / Q000502:physiology*; D013069:Speech Reception Threshold Test