Participating core and specialty programs: Center for Direct Reading and Sensor Technologies, Engineering Controls, and Surveillance.

Industry, academia, and other government agencies use NIOSH information to reduce hearing loss among miners.

  Health Outcome Research Focus Worker Population Research Type
A Hearing loss Noise controls for mining equipment Metal/non-metal mines Intervention
B Hearing loss Hearing conservation approach Stone, sand and gravel mines Intervention

Surveillance research

C Hearing loss Quiet by design (manufacturing quieter equipment) All mines (esp. coal, metal/non-metal) Intervention
D Hearing loss Understanding cumulative noise exposure levels Non-machine operators who work in mines Surveillance research

Activity Goal 2.5.1 (Intervention Research): Conduct studies to develop and assess the effectiveness of interventions to prevent noise overexposures among mining workers.

Activity Goal 2.5.2 (Surveillance Research): Conduct surveillance research to develop new methods and tools to track noise exposures to reduce hearing loss among mining workers.


Noise-induced hearing loss is a pervasive concern in the mining industry. Large machinery performing crushing, cutting, and conveying processes in relatively tight-quarter conditions leads to a high level of noise exposure of the machinery operators and others working in the vicinity. The mining sector has the highest prevalence of hazardous workplace noise exposures (76%) among all industrial sectors [Tak et al. 2008]. Despite engineering and administrative controls implemented to reduce noise, miners continue to exhibit a high prevalence (24%) of hearing difficulty [Tak et al. 2009]. A recent NIOSH evaluation of over 1 million audiograms indicates that mining has the highest prevalence, 27%, of hearing loss among industries sampled, with the average industry prevalence at 18% [Masterson et al. 2015]. Mine Safety and Health Administration exposure data indicate average noise exposure exceeding the permissible exposure limit (PEL) across surface and underground coal and non-coal mining sectors. Exceedance values range from approximately 7% to 18% [Roberts et al. 2017], which is greater than the 4-16% of the general, low-noise-exposed population [Tak et al. 2009].


Ongoing surveillance efforts regarding noise exposure and hearing loss in the industry are necessary to identify future research needs and to assess the effectiveness of past work. Although larger scale industry-wide surveillance initiatives are ongoing, there must be a specific focus on mining to gain a full, accurate understanding of the noise problem by working area and job type. No information exists on the actual use of hearing conservation programs in mining, beyond noting the presence or absence of audiometric testing and the use of hearing protection devices. Continued and expanded surveillance efforts are needed to fill these critical gaps in knowledge.

Currently, in the U.S., mining equipment manufacturers are not held to sound level limitations. Equipment operators are in turn exposed to high noise levels from operating original equipment and the only solutions is add-on noise controls, administrative controls or use of PPE. Focus must be placed on designed quieter equipment from the start, therefore reducing the noise for administrative and personal protective controls. Two of the only facilities in the country with the capability to conduct noise evaluations on large mining machines are located at NIOSH.

In addition, NIOSH researchers have developed relationships with the relatively small mining community that enhances their abilities to access mines to conduct field studies. This access to sites and mine workers enhances the relevance of the research by assuring that strategies, products, or concepts will be accepted by the end user, and can be effectively produced (if required) by a manufacturer. Reducing the noise at the source through a quieter original design or through use of engineering noise controls is the preferred method to reduce overall noise emission and in turn noise exposure of equipment operators.

Masterson EA, Deddens JA, Themann CL, Bertke S, Calvert GM [2015]. Trends in worker hearing loss by industry sector, 1981-2010. Am J Ind Med 58:392-401.

Roberts B, Sun K, Neitzel RL [2017]. What can 35 years and over 700,000 measurements tell us about noise exposure in the mining industry? International journal of audiology 56(sup1):4-12.

Tak S, Calvert GM [2008] Hearing difficulty attributable to employment by industry and occupation: an analysis of the National Health Interview Survey – United States, 1997 to 2003. J Occup Environ Med 50(1):46-56

Tak S, Davis RR, Calvert GM [2009]. Exposure to hazardous workplace noise and use of hearing protection devices among US workers — NHANES, 1999-2004. Am J Ind Med 52(5):358-371.

Page last reviewed: April 24, 2018