Noise-induced hearing loss (NIHL) continues to be a pervasive problem for the nation's workforce, particularly the nation's mining personnel. As one of the leading health and safety organizations in the world, the National Institute for Occupational Health and Safety (NIOSH) in Pittsburgh maintains a Hearing Loss Prevention Program (HLPP) to conduct research to reduce NIHL loss among the nation's miners. This document provides a brief overview of this HLPP, describing some of the research techniques involved in the development of engineering noise controls, methods for the development of administrative noise controls, and some of the products available to the public to protect the nation's workers hearing.

For more than 50 years, the National Institute for Occupational Safety and Health (NIOSH), part of the United States (U.S.) Centers for Disease Control and Prevention (CDC), has been actively working to reduce the effects of noise and ototoxic chemicals on worker hearing. NIOSH has pioneered basic and applied research on occupational hearing risks and preventive measures. The Institute has issued recommendations and promoted effective interventions through mechanisms ranging from formal criteria documents to blogs and social media. NIOSH has conducted surveillance and published statistics to guide policy and target prevention efforts. Over the past five decades, substantial progress has been made in raising awareness of noise as a hazard, reducing the risk of occupational hearing loss, improving the use of hearing protection, and advancing measurement and control technologies. Nevertheless, noise remains a prevalent workplace hazard and occupational hearing loss is still one of the most common work-related conditions. NIOSH continues to work toward preventing the effects of noise and ototoxicants at work and has many resources to assist audiologists in their hearing loss prevention efforts. © 2023 Thieme Medical Publishers, Inc.. All rights reserved.

The National Institute for Occupational Safety and Health (NIOSH) maintains the Pittsburgh Mining Research Division (PMRD) where a wide variety of mining-related health and safety research is conducted. Part of this research is devoted to reducing the incidence of noise-induced hearing loss (NIHL) among the nation's mining workforce. The need for this research is particularly important, as NIHL is the second most common occupational-related disease among miners. Many types of equipment operators are overexposed to noise, and NIOSH has worked to develop noise controls that reduce the sound level at the equipment operator's location and, thus, operator noise exposure. Examples of these include a urethane-coated flight bar chain for continuous mining machines and a drill bit isolator for roof bolting machines. This article discusses the development of a retrofitted noise control package for haul trucks and load-haul-dumps (LHDs) used in underground metal/nonmetal mines. Experimental methods under discussion include dosimetry and time motion studies, to determine when an operator accumulates the most noise dose. Noise source identification techniques are used to determine the primary noise contributors to the sound level at the operator's position. Proof-of-concept testing using rudimentary noise controls is undertaken to confirm that treating the suspected noise sources will actually reduce the sound level at the operator's location. Next, a description is given of the development of noise controls-an iterative process where noise controls are fabricated, evaluated in an acoustic laboratory, refined, and tested again. Those noise controls that show promise are then field tested under actual mine operating conditions.

The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) maintains a noise control program as part of its Hearing Loss Prevention Branch (HLPB). This program utilizes two large acoustic laboratories-a reverberation chamber and a hemi-anechoic chamber-to assist OMSHR engineers with the development and evaluation of noise controls. This paper discusses the design, instrumentation, and use of the NIOSH acoustics laboratories and the important role they play in noise control development and evaluation. The NIOSH reverberation chamber meets the absorption, reverberation time, and test room broadband qualification requirements specified in the ISO 3741/ANSI S12.51 acoustics standard for precision method sound power testing. As part of a qualification testing program, NIOSH conducted an uncertainty estimate for sound power level testing in the chamber. For an overall sound power measurement, this uncertainty estimate was 0.4 dB. The NIOSH hemi-anechoic chamber, which uses Eckel Industries SuperSoft Panels on the walls and ceiling, is used primarily for noise source identification to determine significant noise sources on equipment. Testing was completed to ensure that the chamber functions as a free-field. The SuperSoft panels met NIOSH requirements and the chamber was verified as a free-field per the test room qualification criteria set forth in ISO 3745. ((C) 2012 Institute of Noise Control Engineering.)