The Effects of Individualized Binaural Room Transfer Functions for Personal Sound Zones

Abstract

The extent to which the performance of personal sound zone (PSZ) reproduction systems is impacted by the individualization of Binaural Room Transfer Functions (BRTFs) and the coupling between the listeners' BRTFs was investigated experimentally. Such knowledge can be valuable for deriving rules for the design of high-performance, robust PSZ systems. The performance of a PSZ system consisting of eight frontal mid-range loudspeakers was objectively evaluated with PSZ filters designed using individualized BRTFs of a human listener and generic ones measured from a mannequin head, in terms of Inter-Zone Isolation, Inter-Program Isolation, and robustness against slight head misalignments. It was found that when no misalignments were introduced, Inter-Zone Isolation and Inter-Program Isolation are improved by an average of around 4 dB at all frequencies between 200 and 7,000 Hz by the individualized filters, compared to the generic ones. With constrained head misalignments, the robustness of both filters decreases as the frequency increases, and although the individualized filters maintain higher performance, their robustness above 2 kHz is lower than that of the generic ones. The evaluation also reveals an inter-listener BRTF coupling effect and a detrimental impact on the performance for both listeners when a single listener's BRTF is mismatched.

A multi-loudspeaker binaural room impulse response dataset with high-resolution translational and rotational head coordinates in a listening room

“…The use of BRIRs has been ubiquitous in many audio applications. For example, in spatial audio reproduction with headphones, BRIRs are used as audio filters to simulate or reproduce an immersive and perceptually plausible sounding environment; in loudspeaker-based applications, the frequency-domain counterparts of BRIRs are equivalent to the acoustic transfer functions between the loudspeakers and the listener's ears, based on which audio filters are designed for tasks such as crosstalk cancellation (Cooper and Bauck, 1989;Gardner, 1998;Choueiri, 2018), room correction/loudspeaker equalization (Karjalainen et al, 1999;Lindfors et al, 2022), and personal sound zones (Druyvesteyn and Garas, 1997;Betlehem et al, 2015;Qiao and Choueiri, 2023a). In addition to audio reproduction and rendering, BRIRs have also played an important role in other audio-related tasks, such as sound source localization (Shinn-Cunningham et al, 2005), sound source separation (Yu et al, 2016), and audio-visual learning (Younes et al, 2023).…”