The Influence of Listening to Nature Sounds on Mental Health

Abstract

The sounds of ocean waves, stream, thunderstorm and birds, which are called nature sounds, have a deep connection with the life of human beings in the process of evolution. However, people of today have been away from listening to those sounds. This study aims to prove our hypothesis that listening to the nature sounds can influence our mental conditions. We measured plethysmogram in order to obtain the Largest Lyapunov Exponent (LLE) and the Autonomic Nervous Balance (ANB) as indexes of mental conditions. The subjects were 8 healthy people, including 3 males and 5 females, aging between 16 and 57. The subjects were asked to listen to each of the 4 kinds of sounds, which includes 3 kinds of nature sounds-ocean waves, birds by the stream, and thunderstorm, as well as 1 electronic sound that imitates bird songs for comparison purpose. For each of them, plethysmogram was taken for 10 minutes. In addition, before and after the action of listening to these sounds, we also conducted a respective 5-minute measurement under the condition of no sound. The result implied a possibility that nature sounds have a special effect on our mental conditions. Furthermore, ANB was used to show how nature sounds differ from electronic sounds in this effect. © Springer-Verlag Berlin Heidelberg 2014.