500
Pure Word Deafness results from disconnection between the left hemisphere and what important part(s) of the brain.
The Primary Auditory Cortex and the Thalamus (AND the Corpus Callosum!)
Patients can still hear sounds - auditory information still reaches the non-dominant (right) hemisphere, though language comprehension, which resides on the left hemisphere, is cut off. For this disorder, the corpus callosum must also be severed, not allowing information to travel to the other lobe of the brain.