Can Birdsong and Flowing Water Improve Your Health?

Earth Day has been celebrated each year in April for the past 51 years in support of environmental protection. Most of the research conducted over the last half century has focused on the negative impacts of pollution, but increasingly scientists are looking at the health benefits of being in nature.

Studies have shown that noise pollution interferes with animals finding food and mates, and causes humans increased stress and ailments such as high blood pressure. However, a new study published in Proceedings of the National Academy of Sciences found that people exposed to the sounds of nature, such as birdsong and flowing water, had a 184% improvement in overall health outcomes, with measurable improvements in blood pressure, cognitive performance, and levels of pain.

The study, conducted by conservation biologist Rachel Buxton and a team of researchers from the National Park Service and six universities, analyzed three dozen past studies, conducted over the course of a decade, on the link between human health and natural sound. One Swedish study found that humans recovered better from stress when in virtual nature environments with nature sounds than those in the same surroundings without sound. An Iranian study found ICU patients on ventilators reported less pain when they listened to nature sounds via headphones.

Buxton and her research team also studied where in the US people can go to enjoy the benefits of nature sounds. Through analysis of National Park Service recordings from 221 sites in 68 different national park sites, the researchers found that about 75% of the sites had audible animals more than 75% of the time and about 40% had audible geophysical sounds such as running water more than 75% of the time.

While noise varied widely at various locations in the parks, even the busier parks contained areas with pristine nature sounds and very little unwanted noise, suggesting people need not travel far to enjoy the positive effects of natural sound. Studies have shown that humans benefit from nature sounds even when mixed with unwanted noise like traffic.

Another recent study, conducted in Germany and published in Landscape and Urban Planning, concluded that people that live in areas with higher plant and bird diversity show better mental health. Using mental and physical health data from about 30,000 people, the researchers found that the higher the number of plant and bird species in a region, the healthier the people who live there. The study also found a positive correlation between mental health and proximity to parks and green spaces—the closer the park, the better.

Katrin Rehdanz, professor at Christian Albrechts University in Kiel, Germany, and co-author of the study, is hopeful that as more is learned about the health benefits of nature, urban planners will find ways to incorporate more opportunities for urban dwellers to enjoy nature. She says, “Our results show nature conservation can, indeed, be understood as a means to promote human health. “