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The Modern Evolution of Hearing Conservation Regulations

January 2007

Theresa Y. Schulz, PhD, CCC-A

It is interesting to study the noise standards that have been promulgated in the U.S. over the last decade or so. These regulations are likely to have long-lasting impact. The Occupational Safety and Health Administration (OSHA) Hearing Conservation Amendment (March 1983) continues to have influence not only in the workplace but in the debate over new regulations. Both the Mine Safety and Health Administration (MSHA) and Federal Railroad Administration (FRA) regulatory preamble documents state the desire to be consistent with OSHA. An examination of Table 1 [PDF], which compares the major components of the three regulations and the 1998 NIOSH "best practices" criteria, depicts the extent to which that intent is met.

There has been some regulatory activity in the last decade which may give some hope for evolution and updating based on the wealth of science that has occurred during the last quarter of a century since the OSHA regulation was enacted. However there has also been some "back-sliding" toward more lenient standards.

The MSHA noise standard made regulatory progress in September 2000 by emphasizing engineering and administrative controls, followed by personal protective equipment, in the hierarchy of noise intervention. MSHA's requirement for technician certification (today only available from CAOHC) also strengthened the training requirements for audiometric testing in hearing conservation programs and MSHA also added the requirement of dual hearing protection at 105 dB TWA.

There were many subtle differences between OSHA and MSHA based on comments and a desire to clarify some of the vague aspects of the OSHA noise standard, and meet the needs of the regulated mining industry. One example pertains to the ceiling for exposures. OSHA says, "no exposures > 115 dBA," which is interpreted to mean no unprotected exposures above that level, giving credit for the assumed effectiveness of hearing conservation programs, hearing protection devices, and administrative and engineering controls. MSHA specified that a "P" code 1violation be issued for any protected or unprotected exposures >115 dBA.

The Federal Railroad Administration (FRA) noise standard for railroad operating employees, which went into effect February 26, 2007, was expressly based on the OSHA standard but also uses MSHA for comparison. The preamble states that the FRA defers to OSHA as the "primary regulator of noise in the workplace," but also acknowledges the need for some departure from the OSHA regulation (FRA Preamble II.B). As an example, FRA requires testing at 8000 Hz "because it will allow employers to identify hearing loss sooner." The FRA rejected MSHA's hierarchy of noise controls in favor of requiring specific engineering interventions and focusing on appropriate hearing protection which would still allow communication and audibility and identification of excessive noise through mandatory "excessive noise reports." 2Where OSHA has no specific mandate requiring employees to take advantage of the employer-paid audiogram, it has been traditionally a condition of employment and is generally accepted that OSHA-covered workers require an annual audiogram. MSHA addressed this issue in its preamble; however, they made no significant change. MSHA employers are required to offer annual audiograms but MSHA stopped short of requiring employees to comply with annual audiometric testing. The MSHA preamble does allow that mine operators can also make audiometric monitoring a condition of employment. FRA requires employees to complete audiometric testing and hearing conservation training only every three years, but requires that training be offered at least once a year.

The FRA loosened some OSHA requirements as well:

  • Audiometric retest can occur within 90 days of the periodic test vs. OSHA's 30-day requirement;
  • Employees must be notified within 30 days about changes in their hearing vs. OSHA's 21 days;
  • Exposures up to 120 dBA are allowed for up to 5 seconds, citing the safety issue of needing horn blasts to warn the public of oncoming trains.

The FRA states that audiologists or physicians are responsible for the audiometric testing in a hearing conservation program and further qualifies that the physician must have "experience and expertise in hearing and hearing loss."

There appears to be a general reluctance to deviate too far from the OSHA regulation, however. As an example, FRA wrote to OSHA asking of any plans to move from a 5-dB to a 3-dB exchange rate. OSHA replied that there were no such plans and FRA has stayed with 5 dB despite recommendations from experts in the field to the contrary.


One would hope that employers would want to use "best practices" rather than being minimally compliant but the realities of the workplace reveal the unfortunate focus on minimal compliance. The preamble documents for these regulations are rich with information. One would also hope that with the evolution of hearing conservation regulations each would "build" on its predecessors. In some aspects that has occurred, but in others the new regulations tear down the gains made by previous regulations. See if you think there is "progress" or "regress" as you read Table 1 [PDF] from left to right.

1A "P" Code is an administrative device to document (in an MSHA database) when overexposure conditions remain despite the implementation of all feasible engineering and administrative controls to reduce the miner's noise exposure to or below the Permissible Exposure Limit (PEL). The term "P" Code derives from the requirement to wear protective equipment (e.g. HPDs).

2The term "Excessive Noise Report," refers to a report filed by a locomotive cab occupant that indicates that the locomotive is producing an unusual level of noise such that the noise significantly interferes with normal cab communications or that the noise raises a concern with respect to hearing conservation. The employee is required to report such excessive noise and the training requirements include how and when to make an excessive noise report. The railroad is required to respond to each report.

This article first appeared in the Council for Accreditation in Occupational Hearing Conservation (CAOHC) newsletter, Update, in the winter 2007 issue. It was reprinted in the Vol. 7, No. 2, March/April 2008 issue of Access Audiology with the permission of CAOHC.

About the Author

Theresa Y. Schulz, PhD, CCC-A is a Team Leader at the NIOSH Pittsburgh Research Laboratory, Hearing Loss Prevention Branch, the President of the National Hearing Conservation Association (NHCA) and a former Chair of CAOHC. She can be contacted at

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