Wind comfort and emotion can be changed by the cross-modal presentation of audio-visual stimuli of indoor and outdoor environments

The development of methods to simulate the sensation of wind that can promote relaxation and elicit positive emotional responses has become a topic of interest with the widespread adoption of virtual and augmented reality systems. Previous studies have simulated natural wind by varying wind speed in a controlled environment or moving a large flow of air through an area. In contrast to such approaches to modulate physical airflow, the use of multisensory stimuli to alter the impression and sense of comfort provided by a simulated wind has rarely been considered in previous research. If visual and auditory stimuli affect wind comfort, a multisensory design should be considered for relaxation systems that use wind effects. Therefore, we experimentally measured wind comfort and associated emotions when participants experienced outdoor and indoor virtual environments through immersive virtual reality to investigate whether cross-modal effects of variations in audio-visual stimuli would impact the relaxation effects associated with a virtual wind. The results show that the virtual environment of an outdoor meadow and the sound of natural wind significantly improved users' subjective experience of comfort and openness associated with the wind, as well as their emotional state. Simulated natural wind reduced mental stress compared to a condition without wind, as shown by questionnaires and biometric data. The results of this study indicate that multisensory stimuli conveying natural impressions and simulated natural wind are effective for wind-based relaxation.