The Effectiveness of the Navy's Hearing Conservation Program

Abstract

The purposes of this study were to determine the incidence of significant threshold shift (STS) for a large number of Naval fleet personnel, evaluate hearing conservation program (HCP) compliance for a large number of Naval ships, and determine whether two currently used compliance measures are useful means of evaluating HCP effectiveness. Data were collected from 12,492 medical records of 154 ships/submarines regarding STS incidence and follow-up, percent of valid audiograms, and other HCP elements. Data analyses suggested that STS incidence (29%) and follow-up compliance (62%) among fleet personnel may be too high and low, respectively, although audiogram compliance is 80.0 to 92.9%. Also, checklists commonly used to evaluate HCP compliance were not highly correlated with STS incidence. The data support literature recommendations for audiometric data base analyses to evaluate HCP effectiveness and for training for medical officers involved in the HCP. Recommendations and future implications are discussed.

Methods for evaluating temporal trends in noise exposure

“…There are many examples of studies which have examined audiometric results in an attempt to determine the effectiveness of HCPs, including studies of longitudinal data across one (Savell & Toothman, 1987; Brink et al, 2002) or multiple (Lee-Feldstein, 1993; Dement et al, 2005) facilities within the same industry or military occupations (Wolgemuth et al, 1995; Muhr & Rosenhall, 2011)Several studies that have utilized audiometric results to analyze HCP effectiveness have found that audiometric test results do not align well with categorized noise exposures (e.g., “high” vs “low”) (Bohnker et al, 2002). Only a few studies have also evaluated quantitative noise exposures with regards to HCP performance (Savell & Toothman, 1987; Lee-Feldstein, 1993; Davies et al, 2008), and some have determined that categorized exposures are more useful than continuous quantitative estimates (Heyer et al, 2011).…”

NAC for noise: From the bench top to the clinic

“…It is estimated that 16% of disabling hearing loss in adults worldwide is due to occupational noise (Nelson et al, 2005). The military is one of the world's most noise hazardous occupations, and NIHL in the military continues to be an acute and costly problem despite hearing conservation programs emphasizing personal hearing protection devices (HPDs) (Bohnker et al, 2002;Wolgemuth et al, 1995). Hearing damage from acoustic trauma accounts for up to 47% of all wounded in action evacuations from Operation Iraqi Freedom and Operation Enduring Freedom and is the fourth leading reason for medical referral for combatants returning from deployment.…”

Pharmacological rescue of noise induced hearing loss using N-acetylcysteine and acetyl-l-carnitine

“…The ''3 dB halving rule'' which states that at 85 dBA sound intensity, exposures are limited to 8 h, and for every 3 dB increase in sound intensity, the time in noise should be reduced by half (at 100 dB intensity the occupational exposure time is limited to 15 min). Wolgemuth et al (1995) analyzed audiometric data that was collected from 12,492 medical records of 154 ships/submarines regarding significant threshold shift (STS) incidence and found an average 29% STS rate among fleet personnel of different ranks and job descriptions after one six-month exercise. As an additional hazard, there appears to be a synergistic effect of noise and jet fuel fumes, and industrial solvents causing a greater loss of hearing (Lataye et al, 2000(Lataye et al, , 2005Kaufman et al, 2005;Kim et al, 2005).…”