Evaluation of Virtual Acoustic Environments with Different Acoustic Level of Detail

TL;DR

This study investigates how varying the level of detail in virtual room acoustics affects perceptual realism, showing that significant simplifications can still preserve key auditory perceptions in virtual environments.

Contribution

It demonstrates that reducing the acoustic level of detail in simulations does not significantly impair perceived plausibility and externalization, informing efficient virtual acoustic rendering.

Findings

Strong reduction in ALOD maintains perceptual plausibility.

Number and accuracy of early reflections are less critical.

Diffuse late reverberation is essential for realism.

Abstract

Virtual acoustic environments enable the creation and simulation of realistic and ecologically valid daily-life situations with applications in hearing research and audiology. Hereby, reverberant indoor environments play an important role. For real-time applications, simplifications in the room acoustics simulation are required, however, it remains unclear what acoustic level of detail (ALOD) is necessary to capture all perceptually relevant effects. This study investigates the effect of varying ALOD in the simulation of three different real environments, a living room with a coupled kitchen, a pub, and an underground station. ALOD was varied by generating different numbers of image sources for early reflections, or by excluding geometrical room details specific for each environment. The simulations were perceptually evaluated using headphones in comparison to binaural room impulse responses measured with a dummy head in the corresponding real environments, and partly using loudspeakers. The study assessed the perceived overall difference for a pulse, and a speech token. Furthermore, plausibility and externalization were evaluated. The results show that a strong reduction in ALOD is possible while obtaining similar plausibility and externalization as with the dummy head recordings. The number and accuracy of early reflections appear less relevant, provided diffuse late reverberation is appropriately accounted for.