National Parks contain natural soundscapes that have the potential to create desirable health outcomes in people. This finding is part of a large, recently published meta-analysis examining the impact of natural audio on visitors’ biomarkers.
In the introduction to Rachel Buxton, a conservation scientist at Carleton University in Ottawa, meta-analysis, she references one study that measured how various factors like sleep loss and disease removed “healthy life years,” from society — an interesting metric, and found that 650,000 years of life in a healthy state are lost through noise pollution — 1000% more than cardiovascular disease.
Sounds cause reactions in every known vertebrate, and most animal and even plant life have evolved to perceive sound as an important way of navigating the environment, finding food and mates, and avoiding danger. Therefore the obscuring of sounds by noise pollution can cause a lot of detrimental neurological effects, such as an increase in cortisol secretion that can lead to negative health outcomes.
One prevailing theory over why natural soundscapes promote healing is that they usually don’t require directed attention, and can allow the sort of “switching off” of auditory focus, something that can almost never be done in the constant stimulation of an urban environment.
In her meta-analysis, Buxton examined 36 studies, which together produced an average of a 28% reduction in feelings of annoyance when listening to natural sounds like birds, wind, and water; perhaps unsurprising. Of traditional markers of health, such as blood pressure, heart rate, and perceived pain, all of which were most strongly reduced (23%) by geophysical sounds of water.