Microsecond Precision of Phase Delay in the Auditory System of the Barn Owl

doi:10.1152/jn.01226.2004

J Neurophysiol. Author manuscript; available in PMC 2012 January 30.

Published in final edited form as:

J Neurophysiol. 2005 August; 94(2): 1655–1658.

Published online 2005 April 20. doi: 10.1152/jn.01226.2004

PMCID: PMC3268176

NIHMSID: NIHMS227797

Microsecond Precision of Phase Delay in the Auditory System of the Barn Owl

Hermann Wagner,^1,² Sandra Brill,¹ Richard Kempter,³ and Catherine E. Carr²

¹Institute for Biology II, Rheinisch-Westfölische Technische Hochschule Aachen, Aachen, Germany

²Department of Biology, University of Maryland, College Park, Maryland

³Institute for Theoretical Biology, Humboldt University Berlin, and Neuroscience Research Centre, Charité Medical Faculty of Berlin, and Bernstein Center for Computational Neuroscience, Berlin, Germany

Address for reprint requests and other correspondence: H. Wagner, Institut für Biologie II, RWTH Aachen, Kopeinikusstraβe 16, D-52074 Aachen

The publisher's final edited version of this article is available free at J Neurophysiol

See other articles in PMC that cite the published article.

Abstract

The auditory system encodes time with sub-millisecond accuracy. To shed new light on the basic mechanism underlying this precise temporal neuronal coding, we analyzed the neurophonic potential, a characteristic multiunit response, in the barn owl’s nucleus laminaris. We report here that the relative time measure of phase delay is robust against changes in sound level, with a precision sharper than 20 µs. Absolute measures of delay, such as group delay or signal-front delay, had much greater temporal jitter, for example due to their strong dependence on sound level. Our findings support the hypothesis that phase delay underlies the sub-millisecond precision of the representation of interaural time difference needed for sound localization.