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While information on aircraft noise is limited, the studies and data GAO reviewed suggest that aircraft cabin and cockpit noise levels likely do not exceed the noise exposure standard established by the Occupational Safety and Health Administration (OSHA). None of the studies GAO reviewed, which included eight that measured noise in the cabin and four that measured noise in the cockpit, found levels that clearly exceeded the OSHA standard, though two of the studies found that noise over long durations in certain types of aircraft may reach the more restrictive exposure limit published by the National Institute of Occupational Safety and Health (NIOSH). OSHA and the Federal Aviation Administration (FAA) have received few complaints from crewmembers related to aircraft noise levels. For example, since assuming authority to enforce its noise standard in the cabin, OSHA has received two complaints related to ambient aircraft noise out of more than 600 complaints related to commercial aviation. No reports related to aircraft noise were submitted to four of FAA’s safety-related databases in the last 5 years. Also, over the past 5 years, the Aviation Safety Reporting System (ASRS), which is a safety database maintained by the National Aeronautics and Space Administration (NASA), has received 10 reports about communications difficulties caused by normal ambient noise levels out of more than 26,000 total reports on safety incidents. Officials from the four aircraft manufacturers GAO spoke with said that they test cabin and cockpit noise levels in each new model of aircraft they produce and have found noise levels below OSHA’s standard. Officials from the eight selected airlines in GAO’s review said that they have conducted testing of cabin noise levels and have also found noise levels to be below OSHA’s standard. Officials GAO interviewed from the labor groups representing pilots and flight attendants told GAO that while noise levels likely do not exceed the OSHA standard, they believe crewmembers nonetheless are sometimes exposed to unsafe levels of noise that could result in fatigue or hearing loss.

The policies reported by the eight airlines GAO spoke with regarding availability and use of hearing protection for pilots and flight attendants varied. FAA does not generally prescribe airline policies on hearing protection, other than specifying that hearing protection must not interfere with safety-related duties. Officials from all eight airlines said that they allow pilots to wear hearing protection such as earplugs or noise-reducing headsets, and officials from five of the airlines said that they allow flight attendants to wear ear plugs onboard the aircraft in operation. However, officials from three of the labor groups GAO interviewed said that the number of crewmembers using hearing protection may be limited, and for pilots, reasons for this limited use could include the comfort, expense, and certain equipment’s lacking compatibility with aircraft communications systems.  

Airline pilots and flight attendants, working in the cockpit and cabin, are exposed to noise from aircraft engines, high-speed airflow, and other sources. Exposure to elevated noise levels can cause permanent changes in hearing, diminished ability to communicate, and fatigue. OSHA, which is responsible for employee working conditions, requires employers to take certain actions when an employee’s noise exposure reaches a level deemed to be unsafe. OSHA enforces its noise requirements in aircraft cabins, and FAA oversees occupational safety—including noise exposure—in cockpits. GAO was asked to provide information on noise levels experienced by crewmembers working in commercial service aircraft and their access to hearing protection. This report examines: (1) what is known about aircraft cabin and cockpit noise levels compared with occupational noise exposure standards and (2) selected airlines’ policies on hearing protection for crewmembers.

To address these objectives, GAO reviewed OSHA’s occupational noise exposure standard, NIOSH’s recommended occupational noise exposure limit, and regulations and guidance from FAA. GAO searched academic, government, and trade publications for studies that measured noise levels inside aircraft and identified 10 studies that met methodological criteria for use. GAO also: (1) reviewed noise-related complaints submitted to OSHA by flight attendants since OSHA began to enforce its noise standard in the cabin; (2) reviewed an FAA analysis of complaints submitted to four of FAA’s safety-incident databases; and (3) analyzed reports that were submitted to ASRS in the last 5 years and that discussed noise-related communications challenges. GAO interviewed officials from FAA, OSHA, NIOSH, seven pilot and flight attendant labor groups, two aviation trade associations, the four largest aircraft manufacturers, and eight mainline and regional airlines with the most passenger enplanements in 2016 and with a range of aircraft types.

GAO is not making any recommendations.

For more information, contact Gerald L. Dillingham, Ph.D. at (202) 512-2834 or dillinghamg@gao.gov.