Natural sights and sounds significantly improve human mental health by lowering stress and boosting positive emotions, according to a study published in the journal Environmental Conservation. Researchers at North Carolina State University found that exposure to green spaces paired with natural audio cues yields immediate psychological benefits, providing support for the idea that urban environments might be made better by incorporating green spaces.
How Nature Sounds and Sights Affect Stress Levels
To measure the psychological impact of different surroundings, investigators at North Carolina State University utilized a randomized trial design. Study participants wore noise-canceling headphones while seated either in a reclaimed nature trail isolated from urban development or in a high-density, busy urban environment.
During these sessions, the headphones played randomized soundtracks consisting of either traffic noise or birdsong. Following each exposure, participants reported changes in their stress levels and how refreshed they felt—a metric researchers refer to as restorativeness. According to Nils Peterson, a professor in the NC State College of Natural Resources and lead author of the study, the emotional shift was immediate.
“For participants who were in a green space listening to the birds, there were significant effects. Positive emotions went up, negative emotions went down, stress went down, and perceptions of feeling restored went up more than any other combination,” Peterson states in the published findings.
Urban Contrast: Gray Spaces and Traffic Noise
The study established a stark contrast between natural settings and high-density urban environments. While green spaces paired with wildlife audio lowered psychological distress, gray urban areas paired with vehicle traffic produced the exact opposite psychological reaction.
Participants placed in urban environments while listening to car sounds reported heightened stress and negative emotional responses. Meanwhile, mismatched scenarios—such as listening to bird sounds in a concrete urban plaza or traffic noises inside a natural green space—generated mixed psychological reactions among the participants.
“On the other hand, you had the complete opposite when participants in a gray, urban area listened to the sounds of cars, and more mixed reactions when the sounds and areas were mismatched,” Peterson explains.
Implications for Urban Design and Public Health
“When you have a really gray space that is going to stress people out and give them negative experiences, if you can change that space so that it has natural sounds, you can ameliorate the downsides of that gray space,” Peterson notes.
While the North Carolina State University research specifically tested the physiological and emotional impacts of bird sounds, the authors point to an existing body of literature supporting the therapeutic value of other natural acoustic inputs, including running water, wind rustling through foliage, and similar environmental audio cues.
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