[4] The subjects in this study were asked to identify which of four names or faces matched a specific famous voice.
[5][6] The clinical and radiologic findings with computerized tomographic scans (CAT scans) in these cases suggest that recognition of familiar voices is impaired by damage to the inferior and parietal regions of the right hemisphere while voice discrimination is impaired by temporal lobe damage of either hemisphere.
In distinguishing voices, it is a complete agnosia, but this is not the case for musical instrument sounds, as they can correctly identify some of them.
Controversy arises in that not all phonagnosics exhibit these symptoms, and so not all researchers agree that it should be attributed to the damage suffered that causes phonagnosia.
Much debate has arisen over the fact that it seems that separate areas of the brain are utilized to handle information from language and music.
QR and KL participated in a study done of auditory and visual tasks accompanied by a brain MRI.
Additionally, KH has suffered from this inability to recognize voices for her whole life, making her the first known case of developmental phonagnosia.
The discovery that phonagnosia can exist without structural damage shows that the disorder can be the result of cognitive abnormalities.
Researchers have suggested that neurons are not making the connections needed for the correct identification of voices, familiar or unfamiliar.
[9] The protagonist in the Tollywood film Prasanna Vadanam is afflicted with this disorder due to brain injury.