I think your information is basically correct, although B.'s deafness was
a slow process.  It took a number of years I think (I could be wrong about
this) before he was totally deaf.  In the final years of his life people
would communicate with him by writing in notebooks while B.  would continue
to speak (or shout).  These notebooks still exist and offer a tantalizing
one-sided glimpse into the later years of his life.

Eric James