How Everyday Sounds Shape Our Brains
The raison d’être of professor Nina Kraus’s Auditory Neuroscience Laboratory, at Northwestern University, is understanding how the brain makes sense of sounds. By conducting studies involving thousands of participants from ages 0 to 90, her team has found that the sonic environments we live in shape the biological infrastructure of our auditory systems, be it in favorable ways (as experienced by those who are bilingual, or who play music) or unfavorable ones (known to those who have experienced hearing loss or concussions). The “hearing brain,” as Kraus calls it, also affects other internal functions, including emotions, movement, and thought processes. Because of the profound ways that sound impacts who we are, the lab’s findings suggest, developing an awareness of soundscapes—and learning how to create and surround ourselves with positive ones—is of utmost importance.
In her new book, Of Sound Mind: How Our Brain Constructs a Meaningful Sonic World (M.I.T. Press), Kraus, who has been studying sound and hearing for more than three decades, explains why the ways we engage with noises—tuning them up or down, in or out—is a constant, lifelong process that changes our brains along the way. We recently spoke with Kraus to learn more about her research, and how we can become more conscious of the audible aspects of our everyday lives.
What got you hooked on studying sound?
Sound is pervasive. It is a huge, often unrecognized part of our lives. It is also present and immediate. I wrote my book, which is a love letter to sound, because sound is what connects us. In a time where people are disconnected, disjointed, divisive, lonely, and alienated, sound is evermore important, and is unfortunately marginalized in our vision-focused world. And yet, we need it [now] more than ever.
Experiencing sound is much different from [listening to] something online, which is curated or re-presented. Sound is something that we experience in the present. When you are having a conversation with someone, there is this reciprocity. [Psychiatrist and scholar] Iain McGilchrist calls it “betweenness,” and it’s probably the most precious form of communication there is.
What kind of effect does sound have on our experience as human beings?
Well, its effect is enormous. What we do in [any given] moment is affected by our life in sound. So how we spend our life in sound—the music we make, the languages we speak, the noise we live in, and the sonic worlds that we create in—shapes who we are biologically.
If you make music, for example, you will [develop] an ability to pick up on certain sound ingredients in a way that another person will not. For a person that speaks another language, there are particular signatures, or aspects of sound, that are enhanced.
You often say that sound is one of the most difficult tasks that we ask our brains to do. Why is that?
First of all, sound is exceedingly fast. It’s here, and then it’s gone. In even just a syllable, there is so much information happening in milliseconds and microseconds, so the sound mind has to make sense of that really quickly. The “hearing brain” is vast, and when we hear, the “hearing brain” engages how we think, how we feel, how we move, and how we coordinate information from our other senses.
Think about the fact that we have been communicating with sound, as a species, for hundreds of thousands of years. Our brains are primed to make sense of sonic information, and yet, the way our culture functions and the way our world is moving, sound is increasingly marginalized. It is getting more and more difficult to hear, because of all of the racket.
Aside from humans, how do other living things, such as animals and plants, respond to sound?
There are certain species that are way more badass than we are in terms of picking up information about sound. There is a whole chapter in my book that is devoted to birdsong. With birds, it’s the males who sing and the females who choose. A female bird has to have a very discriminating hearing sense because she has to decide if a mate is going to be worth it for her offspring based on the strength of his song, and on all of the intricacies and incredible sonic details that are present.
In terms of plants, any plumber will tell you that the roots of a tree will grow in the direction of the plumbing. This is because trees are sensitive to sonic vibrations. Trees operate on a much slower timescale than humans, so it’s much harder for us to notice, but in fact, so many of the biological principles that exist in humans and animals also exist in plants and trees. We are all biological systems and we are all interconnected in many ways, including the way we experience sound.
What are some ways that humans can more thoughtfully engage with sound?
We have a [huge] responsibility to make choices about how we spend our lives in sound. We are constantly getting distracted by little things, like the beeping of the key fob that locks and unlocks your car. Does your neighbor really need to hear this as you come and go? There are thousands of things like this that we can be more mindful of.
There are also many questions we can ask ourselves that relate to how we engage with our sonic worlds: Am I going to make the choice to play a musical instrument? Am I going to live a life that is rich in discussion? Will I choose to engage in a back-and-forth with my kids, or am I going to just park them in front of the television? It is our responsibility to make decisions [about sound] that have a positive ripple effect.