Journal of Comparative Physiology A

, Volume 196, Issue 9, pp 601–612

Properties of low-frequency head-related transfer functions in the barn owl (Tyto alba)

Authors

    • Department of Zoology and Animal PhysiologyInstitute for Biology II, RWTH Aachen
  • Mark von Campenhausen
    • Department of Zoology and Animal PhysiologyInstitute for Biology II, RWTH Aachen
  • Hermann Wagner
    • Department of Zoology and Animal PhysiologyInstitute for Biology II, RWTH Aachen
Original Paper

DOI: 10.1007/s00359-010-0546-0

Cite this article as:
Hausmann, L., von Campenhausen, M. & Wagner, H. J Comp Physiol A (2010) 196: 601. doi:10.1007/s00359-010-0546-0

Abstract

The barn owl (Tyto alba) possesses several specializations regarding auditory processing. The most conspicuous features are the directionally sensitive facial ruff and the asymmetrically arranged ears. The frequency-specific influence of these features on sound has consequences for sound localization that might differ between low and high frequencies. Whereas the high-frequency range (>3 kHz) is well investigated, less is known about the characteristics of head-related transfer functions for frequencies below 3 kHz. In the present study, we compared 1/3 octaveband-filtered transfer functions of barn owls with center frequencies ranging from 0.5 to 9 kHz. The range of interaural time differences was 600 μs at frequencies above 4 kHz, decreased to 505 μs at 3 kHz and increased again to about 615 μs at lower frequencies. The ranges for very low (0.5–1 kHz) and high frequencies (5–9 kHz) were not statistically different. Interaural level differences and monaural gains increased monotonically with increasing frequency. No systematic influence of the body temperature on the measured localization cues was observed. These data have implications for the mechanism underlying sound localization and we suggest that the barn owl’s ears work as pressure receivers both in the high- and low-frequency ranges.

Keywords

Sound localizationInteraural time differenceInteraural level differenceAcousticAuditory

Abbreviations

FFT

Fast Fourier transformation

HRTF

Head-related transfer function

HRIR

Head-related impulse response

ITD

Interaural time difference

ILD

Interaural level difference

Supplementary material

359_2010_546_MOESM1_ESM.pdf (128 kb)
Supplementary material 1 (PDF 127 kb)

Copyright information

© Springer-Verlag 2010