\Deaf"ness\, n.
1. Incapacity of perceiving sounds; the state of the organs
   which prevents the impression which constitute hearing;
   want of the sense of hearing.
2. Unwillingness to hear; voluntary rejection of what is
   addressed to the understanding.
{Nervous deafness}, a variety of deafness dependent upon
   morbid change in some portion of the nervous system,
   especially the auditory nerve.