Technical & Applied Article

Optimizing binaural cue measurement for an acoustic test fixture using a 3D-head shell

¹ Fraunhofer Institute for Digital Media Technology IDMT, Branch Hearing, Speech and Audio Technology HSA, Oldenburg, Germany
² Department of Medical Physics and Acoustics, Carl von Ossietzky Universität Oldenburg and Cluster of Excellence “Hearing4All”, Oldenburg, Germany

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 9 July 2025
Accepted: 3 July 2026

Abstract

Although artificial heads based on the human anatomy are typically used to measure binaural cues in various scenarios, they usually do not provide sufficient acoustic insulation that becomes important, e.g., when measuring at low frequencies or with hearing protectors. For these purposes, an acoustic test fixture (ATF) with high acoustic insulation should be used. However, such ATFs do not reflect the human anatomy, which may affect measurements of binaural cues and other spatially separated sounds. This study investigated differences in interaural time and level differences measured with an artificial head with human anatomy and the GRAS ATF 45CA. The measurements took place inside an anechoic chamber with a circular array of 48 loudspeakers. Moreover, a mountable head consisting of two 3D-printed shells for the ATF based on a KEMAR head was designed to approximate plausible head anatomy while preserving the advantages of an ATF. Binaural cues were also measured with the ATF and attached head shells. The results indicate that differences in binaural cues between the artificial head and ATF largely depend on incident angle and frequency. The differences could be reduced with the additional head shells which make them a reasonable add-on for the ATF when measuring binaural cues.