Scientific Article

Interaural time delay during head movements under loudspeaker-based binaural reproduction

Dynamics and Acoustics Laboratory NTUA, Athens, Greece

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

Received: 8 October 2025
Accepted: 7 June 2026

Abstract

Accurate virtual acoustic image placement relies on precise control of interaural time delay (ITD) and interaural cross-correlation (IACC). For loudspeaker-based binaural playback, crosstalk cancellation can be used to control the binaural signals at the listener’s ears. This study examines how head displacements affect ITD and IACC across anechoic conditions and common two-speaker loudspeaker configurations when binaural content is delivered via a crosstalk cancellation system. Free-field simulations assess cue robustness under frontal, lateral, and rotational head movements. Additional factors such as speaker-to-head distance, head width, and rotational center are considered, while preliminary simulations and experiments illustrate the influence of reflections in rectangular rooms. The findings identify topology-dependent robustness trends for both world-locked and head-locked rendering goals. It is shown that channel separation (CS) is not a reliable predictor of localization-cue fidelity, so CS-based robustness rankings do not necessarily translate to ITD/IACC performance. Additionally, by investigating a broader range of loudspeaker spans than previously reported, a strong span dependence under yaw rotations is revealed. Specifically, larger-span arrangements preserve ITD substantially better than small spans. Retaining ITD information under head movements can be either beneficial or detrimental depending on the reproduction scenario.