The effects of spatialized sounds on the sense of presence in auditory virtual environments: A psychological and physiological study

Although many studies have indicated that spatialized sounds increase the subjective sense of presence in virtual environments, few studies have examined the effects of sounds objectively. In this study, we examined whether three-dimensional reproduced sounds increase the sense of presence in auditory virtual environments by using physiological and psychological measures. We presented the sounds of people approaching the listener through a three-dimensional reproduction system using 96 loudspeakers. There were two spatial sound conditions, spatialized and non-spatialized, which had different spatial accuracy of the reproduction. The experimental results showed that presence ratings for spatialized sounds were greater than for non-spatialized sounds. Further, the results of the physiological measures showed that the sympathetic nervous system was activated to a greater extent by the spatialized sounds compared with the non-spatialized sounds, and the responses to the three-dimensional reproduced sounds were similar to those that occur during intrusions into personal space in the real world. Additionally, a correlation was found between the psychological and the physiological responses in the spatialized sound condition. These results suggest that the physiological measures correlate to the perceived presence in acoustic environments.