Eric Clapton recently expressed concerns that he had tinnitus and was “going deaf.”  No less a musical talent than Ludwig van Beethoven shared these same concerns as he progressed from hearing buzzing in his ears (tinnitus) at age 26  to progressive hearing loss and total deafness  by the age of 44. Yet, he still continued to compose music. He was able to do so by holding a pencil in his mouth and touching the other end to the soundboard of the piano as he played. Using the same principle that makes a bone-conduction hearing instrument work, Beethoven was able to conduct sound vibrations through the pencil to his teeth to his skull bones and into his inner ear.

P.S. By placing a vibrating tuning fork between their back teeth, musicians are able to hear a note via bone conduction, leaving both hands free to tune.