# Where does the noise on spacewalks come from?

ISS astronaut Randy Bresnik recently posted a video on social media from his spacewalk, shot with a GoPro.

You can watch his clip here (Embedding the clip didn't work):

So there is obviously sounds coming from his movements and his suit and so forth.

But why is there a constant noise in the audio? To me it sounds like a really bad recording. Is that just common with GoPros or what is the thing here? Any clever ideas?

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• Combination of poor mic placement and noise from the suit movement, Nasa is working on it nasa.gov/topics/moonmars/features/hatsman.html\ – Martin Beckett Nov 29 '17 at 0:02
• I've added the sound tag. Somewhat related sounds discussed here and here for example. – uhoh Nov 29 '17 at 0:17
• The noise should be structure-borne noise. It is not conducted by air, but within solids. The life support system of the suit generates some noise and it is conducted by the rigid parts of the suit to the mounting of the cam and within the cam to the microphone of the cam. – Uwe Nov 29 '17 at 10:21
• And would you expect uniform noise from that? It is weird because I would assume that the smaller the acoustic system, the lower the average randomness of noise. Yeah life support would be plausible, but what is producing random noise in that? Are there fans or something? Or a steady flow of gas? I would assume that not. – lthz Nov 29 '17 at 10:46
• @lthz: There are fans for a circulation of the atmosphere in the suit and there is a water pump for cooling water circulation. Oxygen is added from the tanks when suit pressure is too low, that is a source of noise too. – Uwe Nov 29 '17 at 13:15

These "sounds" consist of vibrations produced by the astronaut's movements and his suit systems and transferred through his space suit, camera enclosure and PCB the microphone is soldered to plus electrical and digital noise added by the sound processing pipeline.