From the Guidelines
Employers should implement a hearing conservation program when workplace noise levels exceed 85 decibels (dBA) as an 8-hour time-weighted average, incorporating recent advances in noise-induced hearing loss prevention, such as monitoring temporary threshold shift (TTS) and utilizing speech-in-noise audiometry, as highlighted in a 2020 study published in the International Journal of Occupational and Environmental Medicine 1.
Key Components of a Hearing Conservation Program
- Regular noise monitoring to identify areas of high noise exposure
- Annual audiometric testing for exposed workers to detect early signs of hearing loss
- Provision of appropriate hearing protection devices, such as earplugs or earmuffs, and training on their proper use
- Implementation of engineering controls, like sound barriers or equipment modifications, to reduce noise levels
- Maintenance of detailed records of noise exposure measurements and audiometric test results for each employee
Importance of Prevention
Noise-induced hearing loss is permanent and progressive, occurring gradually as hair cells in the inner ear are damaged by excessive noise exposure, affecting about 7% of the population, with occupational noise-induced hearing loss (NIHL) being irreversible, thus its prevention must be considered a priority 1. The incidence of occupational NIHL is still high, reaching about 18% of overexposed workers, emphasizing the need for effective hearing conservation programs, and recent research suggests that monitoring TTS and utilizing speech-in-noise audiometry can improve the prevention of occupational NIHL 1.
Recent Advances in Hearing Conservation
The concept of hidden hearing loss and the translational significance of noise-induced cochlear neuropathy have been discussed in recent studies, highlighting the need for personalized medical guidelines for the prevention of NIHL, taking into account several NIHL risk factors other than those included in the ISO 1999:2013 model, as emphasized in the 2020 study 1. Implementing these recent advances in hearing conservation programs can further reduce the incidence of occupational NIHL and associated social costs, as suggested by the study published in the International Journal of Occupational and Environmental Medicine 1.
From the Research
Components of a Hearing Conservation Program
- A successful hearing conservation program includes provision of hearing protective devices, as mandated by legislation in 1969 and 1983 2
- The program should also include components such as audiometric testing, education, and record-keeping 2
- Interdisciplinary team members play a crucial role in making a hearing conservation program successful 2
Effectiveness of Hearing Conservation Programs
- Studies have shown that hearing conservation programs can be effective in reducing the incidence of noise-induced hearing loss 3, 4
- One study found that the risk of standard threshold shift was reduced by 30% after adjusting for potential confounders and continuous use of hearing protection 3
- However, another study noted that highly exposed workers remain at unnecessary risk even with hearing conservation programs in place 3
Prevention of Noise-Induced Hearing Loss
- Engineering controls are superior to hearing protection devices in preventing occupational noise-induced hearing loss 5
- Effective use of audiometry requires quick categorization of audiograms, and the UK Health and Safety Executive scheme is a useful tool for this purpose 5
- A hearing conservation program can be effective in preventing noise-induced hearing loss, even in populations such as marching band members who are at risk due to high sound-level exposure during rehearsals 6