European Journal of
Neuroscience, Vol. 16, pp. 2207-2213, 2002.
Human cortical representation of virtual auditory space:
Differences between sound azimuth and elevation
Nobuya Fujiki(1,2), Klaus Riederer(3), Veikko Jousmäki(1), Jyrki
Mäkelä(1), Riitta Hari(1,4)
(1) Brain Research Unit, Low Temperature Laboratory, Helsinki University
of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland
(2) Department of Otolaryngology – Head and Neck Surgery, Kyoto University
Graduate School of Medicine, Sakyo-ku, Kyoto, 606-8507, Japan
(3) Laboratory of Computational Engineering, Helsinki University of Technology,
P.O. Box 9400, FIN-02015 HUT, Espoo, Finland
(4) Department of Clinical Neurophysiology, Helsinki University Central Hospital,
FIN-00290 Helsinki, Finland
Email: fujiki@amur.hs.m.kyoto-u.ac.jp
Sounds convolved with individual head-related transfer functions,
but presented through headphones, can give very natural percepts of the three-dimensional
auditory space. We recorded whole-scalp neuromagnetic responses to such stimuli
to compare reactivity of the human auditory cortex to sound azimuth and elevation.
The results suggest that the human auditory cortex analyzes sound azimuth,
based on binaural cues, mainly in the hemisphere contralateral to the perceived
sound, whereas elevation in the anterior space and the lateral auditory space
in general, both strongly relying on monaural spectral cues, are analyzed
in more detail in the right auditory cortex.
Keywords: magnetoencephalography, head-related transfer function (HRTF),
three-dimensional (3-D) sound, azimuth, elevation, binaural cue, monaural
spectral cue.