Listening to one-minute-long audio recordings of forests had positive effects on people's short-term wellbeing, especially when the recordings were from local temperate forests. This is the key finding of an experiment led by the German Centre for Integrative Biodiversity Research (iDiv), the Helmholtz Centre for Environmental Research (UFZ), the Friedrich Schiller University Jena, Leipzig University, the Martin Luther University Halle-Wittenberg, and the University of Freiburg. Study participants residing in Germany perceived soundscapes as more awe-inspiring and restorative when recorded in nearby forests than soundscapes that came from the tropics; higher or lower levels of animal diversity only had small effects on short-term wellbeing. The study has been published in the Journal of Environmental Psychology.
Many of us feel better when walking in a forest or spending time outdoors; however, scientists still do not fully understand whether and how the diversity of animals and plants contributes to wellbeing. So far, results have been mixed, especially when it comes to what we hear. Do forests with more bird and insect sounds make people feel better? And does it matter whether those sounds come from familiar, local forests or from faraway places?
Sounds are a big part of how we experience nature and biodiversity
"Sounds are a big part of how we experience nature and biodiversity — like birds singing when you walk through a forest," says co-first author Kevin Rozario, a doctoral researcher at iDiv, UFZ, and the University of Jena. "However, we still don't really know how the diversity and complexity of sounds affects how people feel, or why some sounds may be more uplifting than others."
To shed light on these issues, the researchers carried out an experiment with 195 students in Germany. Participants listened to one-minute-long audio clips of forests that differed in two ways:
how many animal sounds they contained (few vs. many species), and
whether they came from local temperate or from faraway tropical forests.
Each participant listened to two recordings and answered questions about how they felt, how stressed they were, and how well they could focus before and after listening. They also rated how pleasant and familiar the sounds seemed, and estimated how many different animals they could hear. This allowed the team to assess how familiar the sounds felt and to compare the effects of the actual number of species in the recordings, with what participants thought they heard, i.e., the "perceived animal diversity".
The strongest effects came from sounds that felt familiar
Overall, just listening to one-minute-long recordings of forest sounds — even through headphones — made people feel better: they reported more positive emotions, better focus, and less stress. But the strongest effects came from sounds that felt familiar. Recordings from local forests were rated as more pleasant and more restorative, and they also triggered stronger feelings of awe than sounds from tropical forests.
Having more different animal sounds only helped in some cases—for example, it increased feelings of awe when people listened to local forest recordings. What mattered more was what people thought they heard: when participants believed they could hear more animal species, they felt better overall and less negative. In contrast, sounds that felt complex but were not clearly linked to animals could even reduce positive feelings.
"Our findings show that it is not just about how many species are out there," says senior author Prof. Aletta Bonn, research group head at the UFZ, iDiv, and the University of Jena. "Sounds that remind people of forests they know — like the birds they hear on a walk close to home — seem to have a much stronger positive effect. This provides amazing new insights into the complex ways in which biodiversity and mental wellbeing are connected."
