The term Phonagnosia refers to an inability to recognize familiar voices or to discriminate between unfamiliar ones. It is an auditory disorder resulting from brain damage. The ability to recognize familiar voices is impaired by damage to several regions of the right parietal lobe, while an impaired voice discrimination is associated with damage to the temporal lobe in both hemispheres.
Researchers from UCL document the case of a 60 year old woman known as K.H, who says that she has been unable to recognize familiar voices for as long as she can remember. She told the researchers that she avoids answering the telephone, and for many years she has only answered "booked calls". Due to this reason, her friends and co-workers pre-arrange their calls, so that she knows who to expect when she answers the phone at a certain time.