Nature sounds and their effect on the brain and nervous system

Research into the effect of natural sounds on the human organism has become increasingly important in recent years. Various studies show that listening to natural sounds such as birdsong, the sound of water or wind can not only increase subjective well-being, but also have measurable effects on physiological and cognitive processes. This article presents the current state of research and sheds light on the underlying neurobiological mechanisms.

Stress reduction through activation of the parasympathetic nervous system

A recurring theme in research on natural sounds is the reduction of stress. It is well documented that natural sounds affect the autonomic nervous system, particularly the parasympathetic nervous system, which is responsible for the "rest-and-digest" responses in the body. The auditory perception of natural soundscapes has been shown to promote parasympathetic activity, as evidenced by a reduction in cortisol levels, heart rate and blood pressure (Wu et al., 2024).

The neurobiological mechanisms behind this response are attributed to an activation of certain brain regions such as the amygdala, which is associated with the processing of emotions and the stress response. Nature sounds modulate the activity of the amygdala and at the same time promote activation of the prefrontal cortex, a region associated with cognitive control of emotions and stress reduction.

Cognitive effects: Attention and "soft fascination"

The cognitive effect of natural sounds is often studied in the context of Attention Restoration Theory (ART). This theory states that natural environments and sounds support the brain's ability to regenerate attention. In urban environments, which are often characterized by loud and complex sounds, the brain's selective attention is heavily taxed, leading to mental fatigue. Natural sounds, on the other hand, provide a form of "soft fascination" that allows the brain to relax and restore cognitive resources (Aletta & Kang, 2023).

A study showed that subjects who listened to nature sounds after mental fatigue showed a significant improvement in their cognitive performance, especially in tasks that required continuous attention. This indicates that the auditory perception of nature sounds activates the prefrontal cortex and supports the recovery of cognitive functions.

Effects on the autonomic nervous system and the cardiovascular system

Another important area of research is the effect of natural sounds on the autonomic nervous system and the cardiovascular system. Studies show that listening to nature sounds leads to an activation of the parasympathetic nervous system, which increases heart rate variability (a marker for stress regulation) and lowers blood pressure. These effects were observed in both healthy adults and people with cardiovascular disease (Wu et al., 2024).

The neurobiological basis of this effect is attributed to the interaction between the auditory cortex, the limbic system and the hypothalamus. The hypothalamus controls the autonomic nervous system and is responsible for regulating stress reactions. Natural sounds can modulate the activity of the hypothalamus and thus trigger a relaxation response that has a positive effect on the cardiovascular system.

Sleep improvement through nature sounds

Nature sounds can also have a positive influence on sleep quality. A study by Blume et al. (2021) shows that listening to nature sounds before bedtime leads to a significant improvement in sleep architecture, including an increase in deep sleep stages (NREM sleep stages). These changes are attributed to a down-regulation of sympathetic nervous system activity and increased parasympathetic activity, leading to relaxation of the body and promoting restful sleep.

In the brain, this effect is mediated by the activity of the thalamic reticular system, which plays a central role in regulating the sleep-wake rhythm. Natural sounds influence the thalamic filtering of sensory information, which means that disturbing ambient noises are perceived less and sleep is less disturbed.

The effect of natural sounds on the human organism can be explained by a variety of neurobiological and physiological mechanisms. They range from the reduction of stress through the activation of the parasympathetic nervous system to the improvement of cognitive functions and the promotion of restful sleep. These findings suggest that the targeted use of natural sounds is not only subjectively perceived as pleasant, but also has measurable effects on health and well-being.

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