The use of finite-difference time-domain (FDTD) simula-
tions is relevant for several applications in virtual acous-
tics. One of these is the numerical calculation of head-
related transfer functions (HRTFs). This study investi-
gates the effect of varying the geometrical complexity
(shape, level of details) of a human head/torso model on
the calculation of its HRTFs using an FDTD solver. In
particular, the interest is on the accuracy of the obtained
simulation results with respect to the human head/torso
model complexity. For that aim, a solution verification
process is undertaken, and a single sphere, a two-sphere
and a human head and torso models are considered. The
results indicate that relatively small 95% confidence in-
tervals on the solution verification results are achieved,
indicating relatively good accuracy for the prediction of
HRTFs up to relatively high frequencies for the single and
two-sphere models considered. However, for the simpli-
fied human head and torso model, a similar accuracy is
achieved only up to a lower frequency.