Effect of laboratory conditions on the perception of virtual stages for music

This manuscript presents initial findings critical for supporting augmented acoustics experiments in custom-made hearing booths, addressing a key challenge in ensuring perceptual validity and experimental rigor in these highly sensitive setups. This validation ensures our proposed methodology is sound, guarantees the reliability of future results, and lays the foundational groundwork for subsequent perceptual studies and the development of robust guidelines for laboratory design in virtual acoustics research. A preliminary study on the effect of the acoustical conditions of three different rooms on the perception of virtual stages for music is presented: an anechoic room, a custom-made hearing booth with insufficient sound absorption, and another custom-made hearing booth with achievable sound absorption. The goal of this study is to assess the impact of these different conditions on the perception of virtual stages for music. The results show that the anechoic room and the hearing booth with achievable sound absorption have a difference between the total sound and the virtual sound below the just-noticeable difference, which means that the virtual sound is not perceived louder than it should. In contrast, the hearing booth with insufficient sound absorption has a difference above the just-noticeable difference, which means that the virtual sound is perceived louder than it should. This study provides a preliminary validation of the proposed methodology for assessing the acoustical conditions of custom-made hearing booths in stage acoustics experiments. Future work will include a more comprehensive analysis of the results, including the effect of different sound sources.

Real-time auralization for performers on virtual stages

This article presents an interactive system for stage acoustics experimentation including considerations for hearing one's own and others' instruments. The quality of real-time auralization systems for psychophysical experiments on music performance depends on the system's calibration and latency, among other factors (e.g. visuals, simulation methods, haptics, etc). The presented system focuses on the acoustic considerations for laboratory implementations. The calibration is implemented as a set of filters accounting for the microphone-instrument distances and the directivity factors, as well as the transducers' frequency responses. Moreover, sources of errors are characterized using both state-of-the-art information and derivations from the mathematical definition of the calibration filter. In order to compensate for hardware latency without cropping parts of the simulated impulse responses, the virtual direct sound of musicians hearing themselves is skipped from the simulation and addressed by letting the actual direct sound reach the listener through open headphones. The required latency compensation of the interactive part (i.e. hearing others) meets the minimum distance requirement between musicians, which is 2 m for the implemented system. Finally, a proof of concept is provided that includes objective and subjective experiments, which give support to the feasibility of the proposed setup.