Assessment of Crewmember Noise Exposures on the International Space Station

Crewmembers onboard the International Space Station (ISS) work and live in a unique workplace environment for a prolonged time period. While on ISS, they are exposed to different noise levels that are produced by onboard equipment, such as fans, exercise equipment, environmental control and life support equipment, and payloads. Noise exposures in ISS pose concerns for human factors and crewmember health risks, such as possible reductions in hearing sensitivity, disruptions of crew sleep, interference with speech intelligibility and voice communications, interference with crew task performance, and reduced alarm audibility. Acoustic dosimeter measurements are conducted onboard ISS every two months and compared to ISS flight rules, in order to assess the acoustic environment to which the crewmembers are exposed, and also to guide recommendations for usage of hearing protective devices. The purpose of this paper is to provide an update on the status of ISS noise exposure monitoring and hearing conservation strategies, as well as to summarize assessments of acoustic dosimeter data collected since Increment 27 (April 2011). Noise exposure levels (sleep, day-time, and 24-hr), LEQ, will be described, as well as the Noise Level Constraint ISS Flight Rule, applications of the Noise Hazard Inventory (NHI), and the Noise Exposure Estimation Tool (NEET). Future directions and recommendations for the ISS noise exposure monitoring program will also be highlighted.