Ludwig Van Beethoven.
Why? His music is WET with emotion. It changes me. Not only does it make me feel, it FEELS me. It's alive. Mozart, Bach, and Handel are all amazing as well, but can be a "dry" at times. Beethoven is never dry. Always fresh, opus after opus.
His music is the kind that can recalibrate the human nervous system.
This is all besides the fact that he was deaf.