Functional ear asymmetry in vertical localization

Vertical frontal mid-saggital plane localization was tested in binaural, monaural left and monaural right ear conditions. Band-pass noise stimuli were presented pseudorandomly through one of four loudspeakers set with an angular separation of 11 degrees. The subject's performance, based on reaction time and mistakes, was continuously recorded. The binaural performance was twice as high as the monaural performance, suggesting that the two ears treat the information in a different and complementary way. The left ear performance was higher than the right ear performance; this strongly suggests a right hemisphere superiority for vertical localization.