Phonagnosia: a dissociation between familiar and unfamiliar voices.

A dissociation between facial recognition and facial discrimination is well known, but investigations of "phonagnosia" (impairment of voice recognition and discrimination) have not been pursued. Using familiar and unfamiliar voices as stimuli, a marked difference between the ability to recognize familiar voice and the ability to discriminate between unfamiliar voices was identified in five patients, and a sixth showed a severe impairment in both tasks. Clinical and radiologic findings in these cases suggest that recognition of familiar voices is impaired by damage to inferior and lateral parietal regions of the right hemisphere, whereas impairment of voice discrimination abilities is associated with temporal lobe damage of either hemisphere. This dissociation of recognition and discrimination of the human voice suggests that these two functions are mediated by different brain structures and may contribute differentially clinical syndromes.