A method to incorporate the effect of clothing accessories in the head-related transfer functions for enhanced binaural experience

Head-related transfer functions (HRTFs) are widely used in applications based on virtual acoustics, including virtual and mixed reality, advanced music experiences, TV shows, and video games. Today, the available sets of HRTFs can even be personalized to provide an enhanced binaural experience. However, when someone wears clothing accessories such as hats, cups, or hoods, the diffractions and reflections that the sound suffers as it reaches the eardrums change drastically. Whenever in a virtual scenario with an avatar wearing such accessories, the employed HRTFs should take their effects into account. This paper presents a method to modify any set of HRTFs to consider the influence of a specific accessory. To this end, we have created a database containing complete 3-D sets of HRTFs measured on a dummy head with different accessories in an anechoic chamber. For each accessory, we propose a novel transfer function that compares the HRTFs with the accessory to those measured in a bare head state. Our algorithm uses this transfer function to easily modify any set of standard HRTFs. This study also allows to evaluate how some accessories change the perceived sound spectrum. For example, the hood of a raincoat produces an obvious comb filter effect.