Philae’s SESAME-CASSE instrument ‘listened’ to the lander’s MUPUS instrument hammer the surface of Comet 67P/Churyumov–Gerasimenko on 14 November 2014.
This sound bite captures stroke number 129, as recorded by MUPUS housekeeping data. (Listen via Soundcloud, here).
For more information, see the blog post: The sound of Philae conducting science