Recovery from localization dominance in the barn owl

Abstract

Barn owls, like humans, localize sounds that arrive directly from a source and are less influenced by reflections that follow after a short delay. Neural responses in the owls’ auditory space map are diminished when a sound duration exceeds that of the reflection’s delay and firing recovers only when the delay exceeds ∼10 ms. Neither the onset‐ nor the ongoing‐delay causes this diminishment. Instead, recovery corresponds with the emergence of a response at the stimulus end, when only the reflection is present. Head‐saccades were measured while manipulating the duration of the reflection‐alone sound segment. The proportion of saccades that each owl made toward the lagging source depended on the duration of the reflection‐alone segment and was independent of the stimulus onset‐delay. The perceptual salience of a reflection, or other lagging sound, may thus depend on the space map’s response to this reflection‐alone segment. [Work supported by NIH, Grants F32 DC008267‐01A1 to B.S.N and DC 03925.]