Scientists say they are closer to pinpointing the root cause of tone deafness by tracking the brain patterns of people with the condition.
About four in every 100 people are unable to enjoy music properly because they cannot distinguish one note from another.
Some had thought the problem lies in the part of the brain that first interprets sound - the auditory cortex.
The Annals of Neurology study suggests other brain areas are at fault, reports BBC.
According to News-Medical.net, findings may have implications both for amusia and for speech learning disabilities, according to lead study author Isabelle Peretz, Ph.D., of the University of Montreal.
Peretz and collaborators at the University of Helsinki assessed brain cell responses to tones across different brain areas using electroencephalography (EEG).
Compared to control subjects, people with congenital amusia show abnormal brain activity in the right half of the brain, consistent with earlier findings by Peretz's group and others.
It may be possible to compensate for amusia by training pitch discrimination abilities. "However, it is likely that the intervention will only be effective in a 'plastic' brain, in children. We see no sign of improvement in adults," said Peretz.
Amusic adults show a normal range of intelligence and have no other brain deficits. They get little payoff from pitch training and typically find it annoying. Their performance on tests of pitch may even decrease with continued testing.