How loud is space?

In the vacuum of space no sound can travel, but inside spacecraft it can get loud. Acoustic Diagnostics is an Italian space agency (ASI) experiment that is looking at astronauts’ hearing on the International Space Station. This timelapse video shows NASA astronaut Andrew Morgan running the final session on 20 March 2020. 

The sessions are relatively passive for crew members as inner ear sensors detect the movement of hairs in response to auditory stimulation. ESA astronaut Luca Parmitano also participated in this study during his Beyond mission. It aims to assess the possible adverse effects of noise and the microgravity environment of the Space Station on human hearing. 

The crew turn on their laptop and don headphones to perform the audio measurements, and use the astronaut app EveryWear to answer questionnaires.  The investigation tests the hearing of astronauts before, during, and after their spaceflight. The investigation compares the relationship between the detection of otoacoustic emissions, sounds naturally generated from within the inner ear, and hearing loss levels when exposed to noisy environments.