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

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 dB 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 dB 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.