Conference Paper
Sound Localization Beyond the Horizontal Plane
AES Conference: 55th International Conference: Spatial Audio · Paper IP1 · August 2014
Abstract
Spatial hearing involves perceptual effects like externalization, distance estimation, apparent source width, listener envelopment, spatial unmasking, and localization of sound sources. In this talk, we will focus on details of the latter effect, in particular, sound localization in sagittal planes, i.e., vertical planes being orthogonal to the interaural axis. While interaural cues are important for sound localization in the lateral dimension, monaural spectral cues are assumed to be most important for sagittal-plane sound localization, allowing to estimate the source elevation within a hemifield and allowing to discriminate between front and back. Spectral cues result from the direction-dependent filtering of broadband sounds by the torso, head, and ear and can be described by the head-related transfer functions (HRTFs). While the encoding of sound directions by HRTFs is an acoustic process, the decoding of those cues involves several auditory processing stages. In addition to the peripheral processing of the cochlea, the dorsal cochlear nucleus (DCN) is assumed to play an essential role. The contribution of the DCN in the model is analyzed. Further, listener-specific factors influencing localization performance beyond the horizontal plane are discussed.
