Some Effects of the Torso on Head-Related Transfer Functions

A numerical method based on the ultra-weak variational formulation (UWVF) is used to calculate three sets of Head-Related Transfer Functions (HRTFs). The three sets are made by combining a hard head with a hard torso, a moderately absorbing torso, and no torso. Each set is sampled for every 50Hz from DC to 24kHz at 21,872 points almost evenly distributed in the far-field, thus providing a spatial resolution of approximately one degree everywhere. Since the results of the numerical simulations are not contaminated by the response of an electro-acoustic chain it is possible to compare the HRTFs of a head-and-torso to the HRTFs of the head only without the risk of interpreting a measurement artifact as a physical phenomenon.