Influence of impulse noise on noise dosimetry measurements on the International Space Station

Abstract

Abstract Objective: Acoustic dosimetry (AD) data collected on the International Space Station (ISS) were analysed to investigate the impact of impulse noise on crew noise exposure. Design: The noise exposure during work (LAeq16h) and sleep (LAeq8h) time, and the number of impulses >115\u2009dB peak that occurred during each measurement activity, were calculated from the AD data. Two parametric studies were used to estimate the effect of 1) impulses in the original data set, and 2) hypothetical impulses of different levels, durations and quantities on LAeq16h. Study sample: Twelve sets of AD data collected on the ISS from November 2017 to October 2018. Results: The ISS work time noise limit (72 dBA) was exceeded in four of the 12 data sets. In three of those, there were over 100 impulses >115\u2009dB peak and the number of impulses was significantly correlated with LAeq16h. However, the impulses only caused a meaningful increase in LAeq16h when the number of occurrences was large (>50), or when both the level and duration of the impulses were large. Conclusions: Continued monitoring of impulse noise data is recommended to facilitate the investigation of exceedances or abnormalities in future AD data acquired on the ISS.