Microsecond precision of phase delay in the auditory system of the barn owl.
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 micros. 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.
Wagner
Hermann
H
Institute for Biology II, Rheinisch-Westfölische Technische Hochschule Aachen, Aachen, Germany
Brill
Sandra
S
Kempter
Richard
R
Carr
Catherine E
CE
D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology; D001933:Brain Stem / Q000502:physiology; D004307:Dose-Response Relationship, Radiation; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005583:Fourier Analysis; D011930:Reaction Time / Q000502:physiology*; D020305:Strigiformes / Q000502:physiology*; D013997:Time Factors