Perspectives On How Acoustical, Non-Acoustical, And User Characteristics Should Be Considered In Multimodal Virtual Reality Research And Application

Abstract

The use of Virtual Reality (VR) environments is becoming more widespread in research and clinical/applied settings, including in the context of hearing research. This is in part due to the ability to recreate realistic, everyday challenges. As such, it is becoming increasingly important to characterize the differences between the acoustical properties of traditional soundbooths and new VR test environments. While there are international standards specifying the necessary acoustical properties of highly controlled sound environments, such as soundbooths, there are no currently specified best practices for the measurement and control of the acoustical properties of multimodal VR systems. In the present paper, we provide a general perspective on how acoustical, non-acoustical (e.g., visual displays, interactive devices), and user (e.g., age) characteristics are important to consider in developing and using multimodal VR systems. As a proof of concept, we report here a protocol for acquiring acoustical measurements (reverberation time, noise level, and signal-to-noise ratio (SNR)) to 

characterize the acoustical properties of a standard soundbooth and compare these measurements to a representative multimodal VR laboratory (StreetLab at the Toronto Rehabilitation Institute). Measurements were made under conditions in which a) no lab equipment was operating, b) lab equipment (computers, fans, projection equipment, treadmills) was operating, and c) experimental stimuli (target speech, competing speech and other background noise such as simulated traffic sounds) were present or absent. We subsequently discuss the potential and unique consequences of these results to auditory perception and performance in younger and older user populations. We also consider the implications for implementing auditory content within multimodal VR systems more broadly speaking. Overall, there is great value in extending the knowledge that has been amassed from hearing research conducted in soundbooths by using the more ecological and realistic testing conditions afforded by rapidly advancing VR technologies. Indeed, such technologies could change the landscape of auditory research and approaches to practice in rehabilitative audiology. However, as these opportunities and technologies evolve, there is a need to establish appropriate guidelines and standards for designing, measuring, and accounting for the acoustical and non-acoustical properties of VR testing environments for research and other applications across various user populations.