You're in a cozy café at lunch time. You suddenly surprise yourself by paying notice to the sounds of chirping birds and flowing water. You feel more grounded, calm, connected. You skip the plastic straw (although you know it does a better job) and opt for the vegan muffin. That serene atmosphere? It's not just setting the mood. It's quietly guiding your choices. A shift in your brain’s decision-making process has just taken place.

Sounds close the gap between pro-environmental intentions and actual choice

A recent study tested the physiological effects of natural sounds on human behavior. When it comes to pro-environmental purchasing decisions, there is always a gap between the intention and the act (the difference between wanting to make eco-friendly choices and actually doing it). Now there is a way to minimize or even close this gap.

The experiment showed that, when compared to unnatural sounds (e.g., noise from a factory), exposure to natural sounds subtly enhanced the focus on green products among people who care about the planet (otherwise referred to as individuals with high EMA—Environmental Movement Activism). Physiologically, this is marked by a lower heart rate and increased brain activity in regions tied to focused attention.

At the same time, the difference in heart rate between exposure to natural and unnatural sounds acts as a strong predictor of the rate of green product purchases. How valuable is this knowledge to marketers? It can play a critical role in designing and testing environmental settings for green advertising campaigns.

How ‘green sounds’ make the brain ‘buy green’

People with strong environmental values often face this inner dilemma: they want to buy eco-friendly products but don't follow through. Psychologists are already familiar with the space between green intention and action. It’s our attempt to balance personal, utilitarian needs with the desire to protect the environment while we consume products and services. But to what extent do we desire this? And how many among us?

This new study offers an answer by having exposed participants to either natural sounds (like birdsong) or unnatural ones (like factory noise) while they viewed a selection of 54 everyday green non-food products. Items such as toothbrushes, towels and umbrellas were presented in two versions: one with a green label and one with a gray label. The environmentally responsible products were described as performing better on environmental protection, with lower energy consumption, reduced pollutant emissions, and ease of recycling and reuse. Non-green products on the other hand, were described as superior in performance, made up of standard materials, yet extremely practical, efficient and reliable.

Sound changes hearts and minds – literally

To process the information that might be influenced by natural sounds, researchers monitored the participants’ heart and brain. Heart rate (number of heart beats per minute) is widely used as an indicator of attention. Usually, when the heart rate slows down, it reveals an enhanced level of attention (Corcoran et al., 2021; Lansink & Richards, 1997). Brain activity was also measured via an electroencephalogram (EEG) and its frequency spectrum. Low and high frequency bands also indicate attention and concentration, specifically during information gathering and selection of products in natural (i.e. marine) and un-natural (urban traffic) settings.

The results of the experiment? Natural sounds have the most pronounced effect on high EMA individuals. This particular group of people actively express interest, support or participate in organized environmental actions. They already display a strong connection to nature.

Their brainwave activity intensified when exposed to natural sounds. Their heart rates slowed. They chose more green products (particularly valid for women, for whom natural sounds have been proven to effectively reduce heart rate [Jo et al., 2019]). It was deduced that the purchase rate of green products can be predicted by monitoring the change in heart rate. Birdsongs helped the participants’ brains and hearts synchronize and align with their existing values in terms of sustainability. In contrast, noisy surroundings (e.g. factory engines) hindered their consideration for environmental protection.

What about people with low EMA? It turns out they are not influenced by natural sounds in their eco-purchases. Their decision-making process is based on the product practical attributes instead. No matter how sensory pleasant the experience of natural sounds in a commercial setting may prove, it fails to raise real concern for the environment among people with low EMA.

Strategic application of the science to influence consumer behavior

Insights from this research can assist in marketing strategy for a range of distribution channels to reduce the gap between intention and purchase action for green products.

Retail operators could introduce ambient birdsong or gentle rain sounds in environmentally-friendly product sections. They have the potential to trigger more purchases without even using persuasive copywriting.

For ecommerce websites, subtle nature sounds can be showcased when the user stumbles upon videos or other interactive content that contains sound. A pro-environmental messaging can be emphasized in ads by using nature audio clips. The same goes for events, where immersive pop-ups with natural sound environments can elicit emotional connections with visitors, in line with their existing green values.

Just remember: natural sounds amplify what's already there—they don't create green values from scratch. So authenticity is key. Overdoing it can feel fake.