Estimating noise-induced permanent threshold shift from audiometric shape: the ISO-1999 model.
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.
Dobie
Robert A
RA
University of California-Davis Medical Center and Dobie Associates, Sacramento, California, USA.
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