The women in it has just had her recently implanted hearing aid turned on and was hearing for the first time in her life. I cannot begin to imagine the sensation.
This was a device made by a company that I used to work for, Envoy Medical. I won't go into all the details, but when I was hired, the product had horrendous corrosion issues. (Not surprising, since you are basically a 0.9 wt% solution of NaCl at 37 oC.) Plastics to the rescue. Silicones and parylenes and other materials did a nice job of stopping the runaway electrochemistry. With the problems fixed, the device regained regulatory approval and is now being successfully implanted.
While it is never what I expected when I started working with polymers, I can honestly say that the proudest moment of my career has been the day that I helped make a woman cry.