Researchers from Magdeburg and Hannover in Germany gave seven classical-music conductors, seven pianists and seven non-musicians a unique hearing test. They placed three loudspeakers in front of them and three to their sides. In random order, the speakers then played a range of standard sounds, but occasionally the scientists mixed in deviant noises. The subjects were asked to press a button whenever a deviant sound came from one particular speaker. According to measurements of their brain activity and error rate, all three groups were equally good at identifying deviant sounds from a designated central speaker. Only the conductors, however, could reliably pinpoint deviant sounds from a particular peripheral speaker.
The same brain areas were active in all three groups, suggesting that conductors do not use different groups of nerve cells for this task. But people normally turn their heads to the source of a sound they find interesting. "Thus, everybody, even a non-musician, is quite good at separating sound sources right in front," says Thomas Muente, the lead author of the study. Conductors, though, have a whole orchestra around them, arranged in a semicircle. "They are forced to extend auditory attention to the periphery," Muente adds. Constant training seems to improve that ability.