Sounds of nature such as the gentle burbling of a brook or the gushing of the wind in the trees may help us relax by physically changing our mind and bodily systems, a new study has found.
Researchers at Brighton and Sussex Medical School in the UK conducted an experiment where participants listened to sounds recorded from natural and artificial environments, while their brain activity was measured in an MRI scanner and their autonomic nervous system activity was monitored via minute changes in heart rate.
They found that activity in the default mode network of the brain (a collection of areas which are active when we are resting) was different depending on the sounds playing in the background.
When listening to natural sounds, the brain connectivity reflected an outward-directed focus of attention.
However, when listening to artificial sounds, the brain connectivity reflected an inward-directed focus of attention - similar to states observed in anxiety, post-traumatic stress disorder and depression.
There was also an increase in rest-digest nervous system activity (associated with relaxation of the body) when listening to natural compared with artificial sounds and better performance in an external attentional monitoring task.
Researchers also noted that the amount of change in nervous system activity was dependant on the participants' baseline state.
Individuals who showed evidence of the greatest stress before starting the experiment showed the greatest bodily relaxation when listening to natural sounds, while those who were already relaxed in the brain scanner environment showed a slight increase in stress when listening to natural compared with artificial sounds, researchers said.