Before I attended a recent Australian Acoustic Society tech talk, I’d never heard of the term biophilic design. I certainly hadn’t thought about how it might relate to the acoustic environment. Fortunately, PhD researcher, Merve Eşmebaşı was gracious enough to present her research on the subject.
Like Soundmask, Merve’s principal focus is on improving human experience through acoustic design. Her research paper specifically focuses on whether opening windows improves the human experience in office spaces, and whether having greenery in the office environment improve the impact of noise.
Unavoidable noise
Why is the research so important? Well, because sometimes noise cannot be avoided. For example, traffic noise in a highly populated city.
Merve’s research focuses on indoor environments where the sound pressure levels are as high as 65dBA. Much higher than would normally be acceptable—around 20-25dbA higher than Australian recommendations, for example. The impact of unavoidable noise can be very harmful, and is something we will cover in more detail in a future blog. But basically, noise increases stress hormones, can raise blood pressure and cholesterol, and can impact blood clotting, among other health problems. It also reduces cognitive performance and productivity.
Fortunately, as Merve’s research shows, reducing the annoyance and feelings of discomfort and disturbance of unavoidable noise can reduce the more serious impacts.
Biophilic design elements
Connecting indoor office spaces to the outdoor environment is one of the main purposes of biophilic design. This can be the addition of green walls, windows that look out onto trees, and so on.
One of Merve’s key findings was that increasing indoor greenery in the visual environment from 0% to 13% contributes to a visually aesthetic, auditory pleasant, and less annoying environment. Importantly, she found that the visual context must be appropriate for the full positive effect. In other words, the greenery must be pleasant for it to be effective. This means including plants that are familiar to the people working in the environment.
Acoustic impacts
The other key research finding was that opening windows improves the indoor environment, even when it makes the space noisier. I found this particularly interesting, especially coming from a city where most low and high rise offices do not have the ability to open windows. Are we missing out here in Australia? On the other hand, Merve’s research took place in a very humid climate where ambient noise levels appear to be higher than in Australia. Again, the appropriateness of the outdoor noise impacted the effectiveness of opening the window. Appropriate noise includes noises that are expected and within the auditory context of the environment.
What about sound masking?
One of the tech talk participants did raise the question of sound masking in the indoor environment. Merve’s research has not yet focused on sound masking in reducing the impact of noise. Until she does, we can rely on thousands of customers who tell us it improves their lives. With our latest system, we have a traffic noise preset, which is specifically tuned to reduce the impact of intrusive traffic noise.