Convention Paper
The Use of Cephalometric Features for Headmodels in Spatial Audio Processing
AES Convention 123 · Paper 7280 · October 2007
Abstract
In two-channel or stereo applications, such as for televisions,
automotive infotainment, and hi-fi systems, the speakers are
typically placed substantially close to each other. The sound
field generated from such a setup creates an image that is
perceived as monophonic while lacking sufficient spatial
``presence'. Due to this limitation, a stereo expansion technique
may be utilized to widen the soundstage to give the perception to
listener(s) that sound is origination from a wider angle (e.g.,
+/- 30 degrees relative to the median plane) using
head-related-transfer functions (HRTF's). In this paper, we
propose extensions to the headmodel (viz., the ipsilateral and
contralateral headshadow functions) based on analysis of the
diffraction of sound around head cephalometric features, such as
the nose, whose dimensions are of the order to cause variations in
the headshadow responses in the high-frequency region. Modeling
these variations is important for accurate rendering of a
spatialized sound-field for 3-D audio applications. Specifically,
this paper presents refinements to the existing spherical
head-models for spatial audio applications.
