Estimation of the low-frequency components of the head-related transfer functions of animals from photographs

Abstract

Reliable animal head-related transfer function (HRTF) estimation procedures are needed for several practical applications. For example, to investigate the neuronal mechanisms of sound localization using virtual acoustic spaces, or to have a quantitative description of the di erent localization cues available to a given animal species. Here two established techniques are combined to estimate an animal's HRTF from photographs by taking into account as much morphological detail as possible. The rst step of the method consists in building a 3D-model of the animal from pictures taken with a standard camera. The HRTFs are then estimated by means of a rapid boundary-element-method implementation. This combined method is validated on a taxidermist model of a cat by comparing binaural and monaural localization cues extracted from estimated and measured HRTFs. It is shown that it provides a reliable way to estimate low-frequency HRTF, which are di cult to obtain with standard acoustical measurements procedures because of re ections.