Mandy Harvy enjoyed signing before she went deaf 10 years ago. After a while, she did something about it. The above video has multiple messages of not giving up, no matter what!
I have a little additional insight into this story since I went through a short-lived, but vaguely similar experience (I still had a pitch reference and knew the tempo with my shoes on). I was in the backup choir for Josh Groban’s In The Round tour through Salt Lake City.
The drums were blaring behind me and all I heard through the monitor was a lot of Josh. Since we were broken up into SATB quartets, no one around me was singing my part, and I couldn’t hear a thing coming out of my mouth. It was all muscle memory all the time. I had never before been able to imagine what it would be like to sing deaf, but it surprised me how doable it is to rely on muscle memory. I can only imagine how much more difficult it would be if I hadn’t heard a thing for a decade.