Sound localization for a virtual sound source in cases of chronic otitis media.

Sound localization in subjects with chronic otitis media (COM) was examined before and soon after ear surgery by means of virtual sound presented by headphones, sound being synthesized based on the head-related transfer functions (HRTFs) in a normal subject. The localization ability in COM patients was usually worse than that in normal subjects, but was better than expected when compared with cases of acute loss. On the other hand, the effects of hearing improvement on localization ability observed in COM patients were smaller than those of simulated acute hearing loss achieved by earplugs in normal subjects. This seems to suggest that the localization cues in patients with chronic hearing loss are different from those under normal conditions.