title: Is this STS work-related? ISO 1999 predictions as an adjunct to clinical judgment.
abstract: BACKGROUND
  Physicians and audiologists are often asked to decide whether standard threshold shifts (STSs) are work-related; epidemiological data can inform these decisions.
  
  
  METHODS
  Predictions of ISO (2013) for both age-related and noise-induced threshold shifts, for the 2, 3, and 4 kHz average used in calculating OSHA STSs, are presented, in tables, graphs, and an Excel spreadsheet calculator. Specifically, the ISO 1999 model estimates age-related thresholds based on age and sex; it estimates noise-induced threshold shifts based on noise level and duration. It specifies that to estimate the final hearing thresholds for a person of given percentile, age, sex, and noise exposure, the expected age-related threshold is to be added to the expected noise-induced threshold shift. Examples show how these data can predict the relative contributions of aging and occupational noise to an STS.
  
  
  RESULTS
  Early-career STSs, especially with high levels of noise exposure, are more likely to be primarily noise-induced. After the first decade of exposure, most STSs will be primarily age-related.
  
  
  CONCLUSIONS
  Given a worker's age, sex, and occupational noise exposure history, ISO 1999 estimates of the expected contributions of aging and noise can supplement clinical judgment.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University of Texas Health Science Center, San Antonio, Texas.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Dobie
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D001301:Audiometry, Pure-Tone / Q000592:standards*; D001309:Auditory Threshold; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000592:standards*; D012015:Reference Standards
keywords: ISO 1999; age-related hearing loss (ARHL); noise-induced hearing loss (NIHL); standard threshold shift (STS); work-relatedness