Monaural occlusion alters sound localization during a sensitive period in the barn owl.

Sound localization was disrupted in young barn owls by chronically plugging one ear. Owls that were younger than 8 weeks of age at the time of ear plugging recovered normal localization accuracy while plugged, whereas those that were older than 8 weeks at the time of ear plugging did not. The end of the sensitive period for the adjustment of sound localization accuracy coincides with the maturation of the head and ears, suggesting that the exposure of the auditory system to stable, adult-like acoustic cues could play a role in bringing the sensitive period to a close. The results demonstrate that, early in development, associations between auditory cues and locations in space can be altered by experience.