Echo sound detection in the inferior colliculus for human echolocation

We studied neural mechanisms for echo sound detection in human echolocation . The model was constructed based on anatomical, physiological and function al observations of the inferior colliculus (IC). The neurons of the network act as cross-correlators, receiving both the contralateral and ipsilateral auditory inputs. We applied to the network pairs of direct sounds (sonar s ounds) and their reflections (echo sounds) from objects. The information ab out distances between the network system and objects is expressed by the de lay times of the reflections with respect to the direct sounds. We demonstr ate that IC neurons tuned in particular interaural onset time differences c ontribute to detect echo sounds, whereby humans perceive obstacles that con front them. (C) 2001 Elsevier Science B.V. All rights reserved.