The avian head induces cues for sound localization in elevation.
Accurate sound source localization in three-dimensional space is essential for an animal's orientation and survival. While the horizontal position can be determined by interaural time and intensity differences, localization in elevation was thought to require external structures that modify sound before it reaches the tympanum. Here we show that in birds even without external structures like pinnae or feather ruffs, the simple shape of their head induces sound modifications that depend on the elevation of the source. Based on a model of localization errors, we show that these cues are sufficient to locate sounds in the vertical plane. These results suggest that the head of all birds induces acoustic cues for sound localization in the vertical plane, even in the absence of external ears.
Chair of Zoology, Technische Universität München, Munich, Germany.
Hans A
HA
Schnyder
School of Biological Sciences, University of Bristol, Bristol, United Kingdom; Active Perception Lab, University Antwerp, Antwerp, Belgium.
Dieter
D
Vanderelst
Chair of Zoology, Technische Universität München, Munich, Germany.
Sophia
S
Bartenstein
Chair of Zoology, Technische Universität München, Munich, Germany.
Uwe
U
Firzlaff
Chair of Zoology, Technische Universität München, Munich, Germany.
Harald
H
Luksch
D000161:Acoustic Stimulation; D000465:Algorithms; D000818:Animals; D001717:Birds / Q000033:anatomy & histology* / Q000502:physiology*; D003463:Cues; D019416:Head Movements / Q000502:physiology*; D009949:Orientation; D013017:Sound Localization