Do hearing protectors protect hearing?
BACKGROUND
We examined the association between self-reported hearing protection use at work and incidence of hearing shifts over a 5-year period.


METHODS
Audiometric data from 19,911 workers were analyzed. Two hearing shift measures-OSHA standard threshold shift (OSTS) and high-frequency threshold shift (HFTS)-were used to identify incident shifts in hearing between workers' 2005 and 2009 audiograms. Adjusted odds ratios were generated using multivariable logistic regression with multi-level modeling.


RESULTS
The odds ratio for hearing shift for workers who reported never versus always wearing hearing protection was nonsignificant for OSTS (OR 1.23, 95% CI 0.92-1.64) and marginally significant for HFTS (OR 1.26, 95% CI 1.00-1.59). A significant linear trend towards increased risk of HFTS with decreased use of hearing protection was observed (P = 0.02).


CONCLUSIONS
The study raises concern about the effectiveness of hearing protection as a substitute for noise control to prevent noise-induced hearing loss in the workplace.
Surveillance Branch, Division of Surveillance, Hazard Evaluations and Field Studies, National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC), Cincinnati, Ohio.
Matthew R
MR
Groenewold
Elizabeth A
EA
Masterson
Christa L
CL
Themann
Rickie R
RR
Davis
D000328:Adult; D001299:Audiometry; D015331:Cohort Studies; D004430:Ear Protective Devices; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D009784:Occupational Diseases / Q000209:etiology / Q000517:prevention & control*; D012189:Retrospective Studies; D016896:Treatment Outcome
hearing protection; noise; noise-induced hearing loss; occupational hearing loss