Effective Hearing Loss Prevention Programs must Consider both Occupational and Non-occupational Noise
Hearing loss prevention programs (HLPPs) are essential to prevent occupational noise-induced hearing loss (NIHL). At a minimum, these programs must include noise measurements, noise controls and worker training; as well as use of hearing protection devices where exposures cannot be reduced through noise controls; and audiometric testing.
One vital but often overlooked topic for effective hearing loss prevention is non-occupational noise. HLPP training that focuses only on occupational noise misses an important opportunity to educate workers on the potential hazards of exposures outside the workplace. While non-occupational noise does not contribute much to NIHL risk among workers with very high occupational exposures (i.e., 8-hour average exposures >90 A-weighted decibels, or dBA), it can contribute substantially to NIHL risk among workers with lower workplace exposures.
One way to assess this potential risk is to consider not just 8-hour occupational noise exposures, but also 24-hour (daily) noise exposures. As part of our Apple Hearing Study (AHS, sph.umich.edu/applehearingstudy/), a study of noise exposures and hearing impacts across America, we have evaluated 24-hour noise exposures among more than 100,000 volunteer participants.
Approximately 25% of more than 29 million measured person-days exceeded the 70dBA 24-hour limit for environmental noise recommended by the Environmental Protection Agency (see chart). Additionally, across more than 16 million person-days of measured headphone sound exposures among AHS participants, about 18% of person-days exceeded the 8-hour (daily) average limit of 75 dBA for headphone exposure recommended by the World Health Organization.
Incorporating non-occupational noise exposures into workplace HLPP training can help workers understand why it is important to limit non-occupational noise exposures in order to reduce the risk of NIHL. By addressing this issue, employers can better prevent NIHL in their workforce and help improve the overall hearing health of Americans.
About the Authors
Richard L. Neitzel, Abas Shkembi, Lauren M. Smith, Xin Zhang and Linyan Wang are Researchers and National Hearing Conservation Association (NHCA) Experts. Visit NHCA at: https://www.hearingconservation.org/