The Biophilic Mind: Relaxing to the Sounds of Nature
Imagine that you are recovering from surgery and are laying in a hospital bed. Or that you have just given a presentation to a group of unconvinced judges. Or that you have just taken a difficult test that you are sure you have failed.
After this stressful event, imagine that someone hands you a pair of headphones and you put them on to hear sounds of nature: the sounds of a babbling brook, birds chirping, and leaves rustling fill your ears. Does this help you calm down?
Recent scientific evidence says that it should.
Several recent studies have looked at the impact of listening to nature sounds on human well-being. One study of patients undergoing mechanical ventilation support in an ICU found that patients who had listened to nature sounds had better blood pressure and less anxiety than those who had not listened to nature sounds.
Another study had male subjects participate in a virtual reality speech-giving test in order to stress them out—after the speech, those who had recovered in a virtual reality forest with nature sounds showed less intense signs of physical distress than those who had recovered in a virtual reality forest without sounds or without any virtual reality.
That’s great! But why would listening to the sounds of nature make you less stressed?
These kinds of studies claim that the sounds of nature are inherently soothing, an idea that has its roots in evolutionary theory. This evolutionary psychology argument claims that because humans evolved in the natural world (and those who were most attuned to the sounds of nature were better able to survive in it), they are predisposed to prefer nature over man-made or artificial environments. This kind of explanation makes sense, but is usually difficult to prove scientifically because these proposed evolutionary changes happened over a long period of time.
Alternately, the authors of this Cognitive Science article make the case that the reason people benefit from natural sounds is the result of a cultural, not evolutionary, process. That is, they propose that people find nature sounds restorative because they were taught that anything associated with nature (including its sounds) is relaxing. Thus, hearing something that you associate with relaxation makes you relax!
To test these competing theories, the authors created a series of studies to understand why people like nature sounds more than urban (or manmade) sounds. They reasoned that if nature sounds were preferred innately (the evolutionary theory), then even when the sounds were unrecognizable, people should like unrecognizable nature sounds more than unrecognizable urban sounds. However, if the preference for nature sounds is only present when the sounds are easy to identify as natural or urban, then the preference for nature sounds is driven by cultural associations between nature and positive feelings (like relaxation or beauty).
What did they find?
First, participants in the study liked natural sounds more than urban sounds when the sounds were easy to identify (i.e., full 5 second clips). However, when the sounds were manipulated to be difficult to identify (by scrambling sections of the sound file or playing a very short “slice” of the original clip), participants’ preference for nature sounds was reduced or eliminated.
Then the authors had one more task for participants—they played the manipulated, hard-to-identify sounds again, but before participants said how much they liked the sounds they had to guess whether the sound came from a natural or urban environment. This time, even though the sounds were hard to identify, participants once again liked the nature sounds more than the urban sounds—regardless of whether they had correctly identified the sounds By making participants think about the sounds in terms of nature or urban sources, the authors forced them to rely on their knowledge of those categories to make their judgments, and because participants were aware that nature sounds are “more pleasant” than urban sounds, they were able to apply those preferences to unrecognizable sound clips.
So why do we find the sounds of nature so relaxing? Well, it just might be because we have learned over time—through personal experience, media narratives, and other cultural signifiers—that nature is peaceful, restorative, or relaxing. So to the extent that nature sounds are recognized as coming from nature, they will make you think of those positive aspects and your body will have a response in line with those expectations.
In a sense, it does not really matter that this phenomenon is not necessarily driven by evolution! If the sounds of nature can make you feel better, then listen away!