Design and manufacture of synthetic pinnæ for studying head-related transfer functions (HRTFs)

A major obstacle in investigating the relationship between the anthropometric properties of an individual’s pinnæ and their corresponding head-related transfer function (HRTF) is the inability to perform controlled experiments free from other confounding factors. We propose a method for performing these experiments by manufacturing a digitally-altered replica pinna. The process involves 3D-scanning a real pinna, performing the desired alterations, manufacturing the replica, and measuring the acoustic properties of the replica. Here, we describe our design and manufacturing methodology, 3D printing a mold of the altered pinna, which is then used to make a silicone casting, as well as our acoustic measurement apparatus and procedures. To demonstrate the effectiveness of our process, we manufactured an unaltered pinna replica and show that the replica has acoustic properties comparable to the original within the range of human hearing ([Formula: see text] kHz).