Article
Towards Modeling Dynamic Head-Above-Torso Orientations in Head-Related Transfer Functions (en)
* Presenting author
Abstract:
The torso and shoulder affect the head-related transfer function (HRTF) by means of reflection and diffraction. The reflection is strongest if the ear, source, and shoulder are approximately aligned and superimposes a comb-filter upon the HRTF magnitude spectrum that can have a depth of up to 5 dB above approximately 700 Hz. In case the direct sound path to the ear is obstructed by the shoulder or torso, they act as a low-pass with a high frequency damping of up to 20 dB. However, relatively little is known about the exact nature of the torso effect for different head-above-torso orientations with current data being based either on simplified geometric models, a neutral head-above-torso orientation, or head-above torso rotations in a single plane. To close this gap, we developed a 3D head and torso model that can rotate its head with three degrees of freedom based on a schematic model of the average healthy young cervical spine. The model can be used to numerically simulate HRTFs for the physically possible range of head-above-torso orientations. The model is intended to analyze the torso effect in more detail and to acoustically model dynamic head-above-torso movements for virtual acoustic reality.