To test stress-reducing sound environments with elements of nature in work places
The project focuses on how to experimentally investigate stress recovery, using typical sounds from nature (such as wind, bird song and sounds from a brook), in a natural context, in an indoor environment. If the study shows that natural elements can accelerate the recovery from high levels of stress, such environments can be used in, for example, hospitals, elderly care and workplaces. In such environments, high levels of stress often occur. Experimental research on recovery from high stress levels in natural environments is limited, as are studies of the effects of sounds in nature.
In a previous experimental study at the VR laboratory in Lund (Annerstedt et al. 2013), we investigated whether virtual natural environments with and without natural sound can mitigate high stress levels on subjects. After inducing stress using a virtual stress test, we investigated physiological recovery in the two virtual natural environments (with and without exposure to natural sounds) and in a control environment consisting of a neutral colored room. Cardiovascular data and salivary cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group that stayed in a virtual natural environment with natural sounds, suggesting faster recovery from high stress onset. The group that recovered in virtual nature without sound and the control group showed no significant recovery. The results suggest a link between nature, nature sounds and stress recovery in a virtual environment.
The results raise new questions that we did not work with in that project: We had, initially, no experimental situation with only natural sounds. How would such an environment work compared to the others? In addition - how would an environment with real plant walls work compared to a virtual environment, with and without natural sounds, as well as with a control environment? In the above experiments, we tested the activity of the sympathetic nervous system (SNS) with cortisol, pulse and HRV, while we tested the activity of the parasympathetic nervous system (PSNS) with T-wave amplitude. We wanted to strengthen the measurement of PSNS activity by using oxytocin measurements in saliva. Excretion of oxytocin shows that the subjects feel calm and secure (Uvnäs-Moberg, 2013). Measurements of oxytocin have never been made in the contexts we conducted.
We have made many attempts to develop this test equipment. Eventually, we succeeded in conducting a test in an environment where we used plant walls, natural sounds and a control environment. The experimental apparatus proved to work very well. The intention is now to use the equipment to test a fictitious workplace: an office. We intend to test sound environments with plant walls and in VR environments as well as with control environments. The hypothesis is that plantwalls with suitable sound environments can lead to a reduction of high stress levels in workplaces (having high stress levels fewer times, and being able to recover faster from high stress levels). Our trials will be reported
Patrik Grahn, Professor, Sveriges lantbruksuniversitet - Alnarp (SLU)
- Annerstedt, M.; Jönsson, P.; Wallergård, M.; Johansson, G.; Karlson, B.; Grahn, P.; Hansen, Å.M.; Währborg, P. 2013. Inducing physiological stress recovery with sounds of nature in a virtual reality forest—Results from a pilot study. Physiology & Behavior 118, 240-250
- Uvnäs-Moberg, K., The hormone of closeness. Pinter & Martin Ltd: New York, 2013.