The sounds of nature have been associated with relaxation of the brain, whether it's the sound of rain, waves, to the sound of insects and birds in a dense forest. In the study, researchers measured the focus of the mind, heart rate, and organ systems such as breathing, body temperature, blood pressure, and digestion. The results of this study of nature sounds were marked by a slowdown in the reaction time of some of the study participants and a decrease in psychological stress such as stress, trauma, and depression. But only a few people can feel calm from the sound of nature, this is because of the different sympathetic responses that everyone has.