Effect of Real and Virtual Environmental Context on Loudness Scaling

There is increasing interest in using virtual/augmented reality applications to represent ecologically-valid complex sensory environments for research and to assess audio and/or visual perception. Visual input is known to modulate auditory experience (and vice-versa), and so it may also influence estimates of perceived loudness of sounds. This has implications for how audio-visual stimuli can be represented within virtual/augmented reality environments to modulate user experience as well as to ensure user experience is both comfortable and accessible. This study investigated the effect of room color and environmental context on loudness perception, using a test of categorical loudness scaling. Loudness categorization was assessed in a real-world room and in four virtual-reality replica environments which varied in color (red/blue) and furnishing (furnished/unfurnished). Results revealed no significant difference in loudness perception between the real-world setting compared to the virtual-reality setting. There was a significant effect of room furnishing on loudness perception when the test environment was blue in color, and there was also a significant difference in loudness perception when sounds were presented in a virtual blue unfurnished room compared to a virtual red furnished room. In both cases, significant effects of color and furnishing were only observed for the categorization of medium-to-loud sound levels, rather than quieter sounds. The loudness categorization results indicate that the visual changes in the virtual environment increase the rate of growth of perceived loudness but only for sounds above medium level.