Even low-level traffic noise can reduce birdsong's stress-relieving effects

A new study from the University of Surrey has found that traffic noise significantly diminishes the health benefits normally associated with listening to birdsong and other natural sounds. Researchers measured the physiological and psychological responses of participants exposed to recorded nature sounds in the presence of simulated traffic noise. The results showed a marked reduction in heart rate variability and a lower reported sense of calm when traffic sounds were added, indicating that the restorative effects of nature audio are compromised by urban noise pollution.

The study, which involved controlled laboratory experiments and field recordings, compared the impact of pure nature sounds to those mixed with typical street traffic levels. Findings suggest that even moderate traffic noise can blunt the positive effects of birdsong on stress reduction and cognitive performance. The researchers recommend that urban planners and public health officials consider noise mitigation strategies—such as sound barriers or green buffers—to preserve the therapeutic value of natural acoustic environments.

These results underscore the growing evidence that environmental noise not only irritates but also undermines the well‑being benefits of nature exposure. The University of Surrey team plans to extend their research to real‑world settings, aiming to inform policy decisions that balance urban development with the need to protect public health through natural soundscapes.