# Listening to a Three‐Dimensional Virtual Reality Sound: Effects on Stress Response of Adults

## TL;DR

This study shows that 3D virtual reality sound can increase heart rate variability, suggesting it may help reduce stress by mimicking real-life autonomic responses.

## Contribution

The study demonstrates that 3D VR sound affects autonomic nervous system activity without impacting cortisol levels.

## Key findings

- 3D sound increased heart rate variability parameters like SDNN, TP, and LF/HF.
- 3D sound had no significant effect on salivary cortisol levels.
- Mono sound effects were intermediate between control and 3D sound conditions.

## Abstract

Virtual reality (VR) technologies utilizing three‐dimensional (3D) sound may offer sensually engaging imitations. Thus, they may lead to relaxation or may provide a way of escaping from disturbing life events. As they have the potential to manage stress, the current study aimed to investigate the effects of VR 3D sounds on the stress axes of the body, namely the autonomic nervous system (ANS) and hypothalamo–pituitary–adrenal (HPA).

Participants (19 men and 27 women, mean age 25.8 ± 10.4 years), wearing on‐ear headphones, did not listen to anything (control) or listened to a mono or 3D sound imitating a real‐life situation taking place in a virtual barbershop. The control phase was immediately followed by mono or 3D phases. Half of the participants in mono and 3D phases were crossed, with 45 min intervals, to control the effect of time and habituation. Reactivity of ANS and HPA was measured by heart rate variability (HRV) and salivary cortisol measurements, respectively. HRV was measured during each phase by a 5‐min continuous electrocardiogram recording. Salivary samples were taken during control recording and 15‐min after mono or 3D sound listening. HRV parameters consisted of both time‐ and frequency‐domain parameters, including standard deviation of R–R interval (SDNN), total power (TP), and low frequency/high frequency (LF/HF), as a measure for sympathovagal activity.

Compared to the control phase, the 3D sound increased almost all HRV parameters (including SDNN, TP, LF/HF, etc., p < 0.05) but did not affect salivary cortisol levels (p > 0.05). Effects of mono sound were in between the control and 3D sound phases.

It seems that a 3D sound imitating a real‐life environment does not affect HPA but increases HRV and sympathovagal balance, suggesting that VR 3D sound is likely to reproduce an ANS response observed in real life.

It seems that a 3D sound imitating a real life environment does not affect hypothalamo–pituitary–adrenal axis but increases heart rate variability and sympathovagal balance, suggesting that virtual reality 3D sound is likely to reproduce an autonomic nervous system response observed in real life.