Ecological Validity of Immersive Virtual Reality (IVR) Techniques for the Perception of Urban Sound Environments

Chunyang Xu,Huan Tong,Francesco Aletta,Jian Kang,Tin Oberman

doi:10.3390/acoustics3010003

Abstract

Immersive Virtual Reality (IVR) is a simulated technology used to deliver multisensory information to people under different environmental conditions. When IVR is generally applied in urban planning and soundscape research, it reveals attractive possibilities for the assessment of urban sound environments with higher immersion for human participation. In virtual sound environments, various topics and measures are designed to collect subjective responses from participants under simulated laboratory conditions. Soundscape or noise assessment studies during virtual experiences adopt an evaluation approach similar to in situ methods. This paper aims to review the approaches that are utilized to assess the ecological validity of IVR for the perception of urban sound environments and the necessary technologies during audio–visual reproduction to establish a dynamic IVR experience that ensures ecological validity. The review shows that, through the use of laboratory tests including subjective response surveys, cognitive performance tests and physiological responses, the ecological validity of IVR can be assessed for the perception of urban sound environments. The reproduction system with head-tracking functions synchronizing spatial audio and visual stimuli (e.g., head-mounted displays (HMDs) with first-order Ambisonics (FOA)-tracked binaural playback) represents the prevailing trend to achieve high ecological validity. These studies potentially contribute to the outcomes of a normalized evaluation framework for subjective soundscape and noise assessments in virtual environments.

Highlights

Received: 17 November 2020 Accepted: 23 December 2020 Published: 25 December 2020Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Ecological validity was introduced in the 1980s to evaluate the outcomes of a laboratory experiment focused on visual perception [1]
We aim to investigate (1) which kinds of approaches can be utilized and integrated to assess the ecological validity of Immersive Virtual Reality (IVR) when humans perceive urban sound environments and (2) which technologies are necessary during audio–visual reproduction to establish a dynamic IVR system to assess the perception of urban sound environments
The audio–visual interaction in these studies was discussed in an attempt to interpret how participants perceived the virtual environments, and the ecological validity was tested with their research questions

Summary

Introduction

Received: 17 November 2020 Accepted: 23 December 2020 Published: 25 December 2020Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Ecological validity was introduced in the 1980s to evaluate the outcomes of a laboratory experiment focused on visual perception [1]. Ecological validity describes the degree to which results obtained in a controlled laboratory experiment are related to those obtained in the real world [2]. Immersive Virtual Reality (IVR) places the user inside an experience, which allows the impact on participants of a new environment with complex social interactions and contexts to be assessed [5–7]. In 2001, Bishop et al [8] reported their non-IVR assessments of path choices on a country walk, and they agreed that faster computers and better display systems make the virtual environment experience more credible. Low ecological validity resulting from non-sufficient immersiveness could be a limiting factor for the generalizability of data collected from laboratory experiments

Objectives

Results

Discussion

Conclusion