Adams has lost his voice due to a bout with spasmodic dysphonia, a condition where the brain forgets how to speak in a normal voice. You can sing, shout, and speak in public, but normal talking is impossible. There are no documented cases of recovery.
This is an amazing story. Rather than gloat about his recovery, Adams asked his readers to share their greatest moments. It’s a fantastic blog post, and it shouldn’t be missed.
(Thanks to Boing Boing for clueing me in to this.)