Predictive factors of occupational noise-induced hearing loss in Spanish workers: A prospective study

Noise Health. 2015 Sep-Oct;17(78):343-9. doi: 10.4103/1463-1741.165064.

Abstract

The purpose of our study was to identify the main factors associated with objective noise-induced hearing loss (NIHL), as indicated by abnormal audiometric testing, in Spanish workers exposed to occupational noise in the construction industry. We carried out a prospective study in Tenerife, Spain, using 150 employees exposed to occupational noise and 150 age-matched controls who were not working in noisy environments. The variables analyzed included sociodemographic data, noise-related factors, types of hearing protection, self-report hearing loss, and auditory-related symptoms (e.g., tinnitus, vertigo). Workers with pathological audiograms had significantly longer noise-exposure duration (16.2 ± 11.4 years) relative to those with normal audiograms (10.2 ± 7.0 years; t = 3.99, P < 0.001). The vast majority of those who never used hearing protection measures had audiometric abnormalities (94.1%). Additionally, workers using at least one of the protection devices (earplugs or earmuffs) had significantly more audiometric abnormalities than those using both protection measures simultaneously (Chi square = 16.07; P < 0.001). The logistic regression analysis indicates that the use of hearing protection measures [odds ratio (OR) = 12.30, confidence interval (CI) = 4.36-13.81, P < 0.001], and noise-exposure duration (OR = 1.35, CI = 1.08-1.99, P = 0.040) are significant predictors of NIHL. This regression model correctly predicted 78.2% of individuals with pathological audiograms. The combined use of hearing protection measures, in particular earplugs and earmuffs, associates with a lower rate of audiometric abnormalities in subjects with high occupational noise exposure. The use of hearing protection measures at work and noise-exposure duration are best predictive factors of NIHL. Auditory-related symptoms and self-report hearing loss do not represent good indicators of objective NIHL. Routine monitoring of noise levels and hearing status are of great importance as part of effective hearing conservation programs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Construction Industry* / methods
  • Construction Industry* / standards
  • Ear Protective Devices
  • Female
  • Health Surveys
  • Hearing Loss, Noise-Induced* / diagnosis
  • Hearing Loss, Noise-Induced* / epidemiology
  • Hearing Loss, Noise-Induced* / etiology
  • Hearing Loss, Noise-Induced* / prevention & control
  • Hearing Tests / methods
  • Humans
  • Male
  • Middle Aged
  • Noise, Occupational* / adverse effects
  • Noise, Occupational* / prevention & control
  • Occupational Diseases* / diagnosis
  • Occupational Diseases* / epidemiology
  • Occupational Diseases* / etiology
  • Occupational Diseases* / prevention & control
  • Occupational Exposure* / adverse effects
  • Occupational Exposure* / analysis
  • Occupational Exposure* / prevention & control
  • Prognosis
  • Prospective Studies
  • Risk Assessment
  • Self Report
  • Spain / epidemiology
  • Tinnitus / diagnosis
  • Tinnitus / etiology