Cities are hustling, bustling hubs of innovation and activity. Our whole modern society revolves around cities, and yet our cities are far from perfect. Among the many things that are annoying about urban life is the noise. In big cities, there’s always some noise, some car horn, or someone screaming.

“You get used to it,” urbanites will tell you — but do you really?

Urban noise is more than just an annoyance, it’s been repeatedly shown to affect mental and physical health. Previous research has linked exposure to traffic noise with increased risks of anxiety, depression, cardiovascular disease, and even neuroinflammation. In contrast, natural environments offer restorative benefits, reducing stress hormone levels and improving cognitive functions.

But what happens when both meet? That is, what happens when you hear both urban traffic and nature soundscapes?

In the new study, researchers tried exactly that. They had 68 student volunteers listen to a 3-minute soundscape:

• a nature soundscape recorded at sunrise in a rural part of West Sussex, UK;
• the same soundscape combined with 20-mile-per-hour road traffic sounds;
• and the same soundscape with 40-mile-per-hour traffic sounds.

The researchers assessed general mood and anxiety before and after the soundscapes using self-reported scales.

Unsurprisingly, they found that listening to a natural soundscape reduced self-reported stress and anxiety levels, and also enhanced mood recovery after a stressor. However, the benefits of improved mood associated with the natural soundscape was limited when traffic sounds were included.

Faster traffic is worse

It’s not uncommon for natural sounds like birds chirping to make their way into urban life. Although cities generally wreak havoc on natural ecosystems, some species are adaptable and can thrive even in small parks or green spaces. If cities have large green areas, it’s all the better.

But as the study suggests, fast traffic can counteract this effect. While the nature plus traffic sounds still had a soothing effect, it was more diminished the faster the traffic.

“Our results show that anthropogenic soundscapes including traffic sounds can mask the positive impact of natural soundscapes including birdsong on stress and anxiety. However, reducing traffic speeds in cities could be a positive intervention for enhancing access to nature,” the researchers write in the study. The study was led by Lia R. V. Gilmour from the University of the West of England.

City planners and policymakers can take valuable lessons from this research. Reducing urban noise pollution by lowering traffic speeds and promoting quieter transportation methods can enhance the quality of life for urban residents. Furthermore, incorporating biodiversity into urban planning can create multisensory environments that are not only visually pleasing but also aurally soothing.

Urban mental health

Green spaces and wildlife corridors in cities provide more than just ecological benefits; they are a lifeline for mental health. They offer an accessible escape from urban stress, allowing residents to recharge and reconnect with nature.

“Our result therefore highlights the importance of the retention of suitable sized urban greenspace that are accessible to the public and large enough to support wildlife populations beyond the reach of anthropogenic pollutants such as traffic noise,” the researchers write. “It is therefore essential that future urban development and expansion occurs with the provision of greenspace included to maximise the health and wellbeing benefits from these spaces.”

The study also acknowledges its limitations. The participant pool consisted primarily of young university students, who may not fully represent the diverse demographics of urban populations. Future research should explore how age, cultural background, and personal connection to nature influence the impact of soundscapes.

However, the findings emphasize the critical role of sound in urban environments. City soundscapes currently induce anxiety and stress, with tangible effects on human health. By prioritizing natural soundscapes and reducing noise pollution, they can instead become a haven for mental well-being.

The study was published in PLoS.