Study on the Effects of Forest Sounds including Inaudible Frequency Bands on Brain Waves

비가청 주파수 대역을 포함한 산림음이 뇌파에 미치는 영향 연구

Purpose: Forest healing programs conducted in forests or recreational forests are known to be very effective in stabilizing the mind and body. This effect is analyzed to be due to the five sensory stimulation factors such as natural scenery, natural sounds, and scents. Among them, this paper focused on sound. In particular, it was estimated that HFC (high frequency components) in the inaudible band among the sounds from the forest would help in stabilizing the mind and body. In this study, forest sounds (audible frequency ~ HFC) collected in deep mountains were applied to subjects and the effect of HFC on stabilizing the mind and body was analyzed. Materials and Methods: Forest sounds were collected from the forest and HFC were provided to subjects using high-performance audio. The subjects consisted of 18 people around 45 years of age (SD3.2), and the experiment was conducted in a chamber where noiselessness was guaranteed. The subjects were divided into two groups and HFC were stimulated auditory and tactile. In order to verify the homogeneity between the groups, the same experiment was repeated by cross-applying auditory and tactile sensations to each group. The change in alpha waves was measured using EEG before and after the experiment. Results: Forest sounds were collected by specifying more than 5 forests. HFC were present in all forests, and most were around 31KHz (31,616Hz, SD772). The effect of HFC was verified by reading alpha waves. Both auditory and tactile groups achieved significant results (p<0.002, p<0.0001), and the tactile group was more effective. Conclusion: This experiment was conducted at a very basic level to verify the existence of HFC in the forest and their effects, but it is thought to be sufficient to confirm the possibility. In this study, HFC collection in the forest was conducted at 2-4 PM in early June. HFC are thought to vary depending on the season, time, location, and surrounding environment. Since the changes in HFC and their effects on brain waves may also vary, further experiments will be necessary. It is thought that various technological and industrial applications are possible.