Even "low-level" noise is unhealthy: A neuroscientist explains how sound and health are connected

Author Nina Kraus says ambient noises around us can put us in a "constant state of alarm"

By Mary Elizabeth Williams

Senior Writer

Published October 17, 2021 7:30PM (EDT)

Woman relaxing while listening to music (Getty Images/PhotoAlto/Sigrid Olsson)
Woman relaxing while listening to music (Getty Images/PhotoAlto/Sigrid Olsson)

Stop for a moment and open your ears. What do you hear?

There's the hum of my building's ancient elevator. The creak of neighbors walking upstairs. A rustle of leaves in the trees outside. A car coming down the street and then continuing on its journey. A toddler crying.

I pay almost no attention to any of it, this rattle of urban life. Yet every aspect, every biological and anatomical particularity that brings this auditory experience to my ears is, for lack of a better word, amazing.

"Every time I hear the story about sound, I'm like a little kid," says neuroscientist Nina Kraus. "I love to hear the story again and again."

After reading her book, "Of Sound Mind: How Our Brain Constructs a Meaningful Sonic World," I get it. The ways in which our hearing — the sense that, as Kraus observes, is "always on" — actually works are remarkable. And the power of sound to help us make connection and make sense of the world are almost limitless.

Drawing on hard science and exuberant appreciation, "Of Sound Mind" examines why we love music, how we make words, and what we mean when we say, "It's good to hear your voice." It also, significantly, advocates for creating our own healthy sonic environments, to "allow sound to change us for the better."

Salon spoke to Kraus recently about noise, sound and the things we choose to listen to. As always, this conversation has been edited and condensed for clarity.

There is a sense that we can't live in silence in general in our world, that now silence is almost intrusive. We don't, as a culture, want that silence. Talk to me about what might be good about having sounds around us, but also what can be really detrimental when we don't have any silences.

First of all, each one of us is different. The case that I'd make in my book is how our [lives] really are rooted in sound, and in how we have assimilated our nervous system and our brain to respond to sound. This is something that happens throughout our lives. It is something that we also are in a position to change if we want. I think a lot of responsibility of curating our sonic world is ours, for ourselves and for our children and in our society. We live in a world where we are constantly stimulated. We're checking our phones, and we keep getting prompts and information about things that we didn't even know were out there. Some of this stimulation robs us our solitude and our personal thought. It robs us of our ability to think, and kind of take stock of who we are and where we are.

The beauty there is the fact that we are all different and there is no recipe. [Some] people will feel more and less comfortable, for example, studying with music or not. We need to know ourselves, and we need to know what are good values from a biological perspective. We know that there is a lot to listen to. I don't really think that we need quiet as much as an absence of noise. Noise is defined usually as a manmade cacophony that we might not even know is there. We've all experienced when the refrigerator turns off in the kitchen or you turn off the overhead light — suddenly it's quieter. You hadn't even realized that the sound was there till you take the sigh of relief.

So much of my message about sound is that sound is under-recognized because it's invisible. We don't often realize how much of an impact it has on our health and who we are. Often, even with respect to this low-level noise that is around us all the time, we are kind of in this constant state of alarm, if you will. Hearing evolved to alert us to danger, to mates, to food. Hearing is absolutely essential to our survival.

Without even being consciously aware of it, the sounds that are going on around us are influencing our brain or influencing our nervous system. I would want to ask everyone, because I ask this of myself all the time, is this necessary? Is it necessary for me to wake up my neighbor when I come home at night and lock my car? Is it necessary when you're at an airport — do we need, every time a boarding pass is scanned — to hear "beep, beep," 235 times?

And also, as a lover of music, music is so intrusive when you're not choosing it — when it's foisted upon you. There are times when having background music is exactly what you want. There are times when it isn't. I think we, every day, need to think about our sonic environment and to realize that we really can honor the sonic environment we think is important so that we can hear the marvels that there are to listen to.

So many people have commented during the pandemic how they have heard sounds of birds and animals and wind in a way that we haven't before. That's the silver lining. That's the beauty of it. What is really interesting from a biological perspective is the fact that the birds are actually singing more quietly. They're singing more intricate songs because they don't have to shout above the din. How cool is that?

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I want to talk about what music does for our learning, how we learn things as children but also how we learn as adults. Most of my family is not musical, so that was interesting to read.

I'm going to push back and say, there's hardly anybody who is not musical. Everyone is musical. We respond to music as babies before we learn words. Before we learn to talk and understand the meaning of words, we hear the music of speech, the rhythms. Any baby will be so delighted if you sit them on your lap and take their little feet and clap them together and move them in rhythm. Think about when your baby's crying — what do you do? You rock him, you bounce him. My view is that music should be a part of every child's education and everyone's education throughout their lives. We're not talking about the goal of becoming a professional musician in any way, but everybody loves to sing.

People who are exceptional at music and people who really don't engage with it at all are at the tail ends, are just a few percent of people. In fact, everyone else is musical. Why is this? It's because sound is so important. One of the reasons it's important is that it connects us. The hearing brain is vast and the hearing brain engages how we think.

How we feel, how we move, how sound is incorporated with our other senses, all of the many invisible ingredients of sound, all of these things come together in the hearing brain — and music is the jackpot. Music engages all of these things so strongly to the extent that beyond learning to make music, one is learning and strengthening one's communication skills.

Making music also strengthens our sense of timing on multiple time scales, from microseconds to seconds. We need those same ingredients for language. We find that kids with language impairments have weaknesses in the brain's ability to process this information. We know this because we can measure sound processing in the brain with scalp electrodes.

As I'm talking to you now, the neurons in your brain that respond to sound are producing electricity. We can measure that electricity, and we can see how good a job your brain is doing at processing the different ingredients of sound. We can see, where are your strengths? Where are your bottlenecks? What we can see resoundingly is that the ingredients that are important and that are strengthened with making music are the ones that we need for processing language.

To that point, you also mentioned auditory learning in the book. So what does that look like when we are sound of mind and sound learners?

There is this differentiation about being auditory or visual learner. If you think about the biology, these things are not compartmentalized. They're not separate. 

Probably the best example is Beethoven, who lost his hearing. He used his sound mind to instruct and to create some of the most beautiful music that we can ever experience, because sound engages so much of our brain. That's why you can see that if you strengthen your sound mind, you are strengthening so many different parts of you. We are experiencing the world with how we think and feel and move and interact with our other senses.   

You talk about the limbic reward system. A lot of us have been longing for and missing just touching each other, smelling each other. I have a kid who's away at college and I feel that dopamine rush when she calls. The sound of each other's voices is such a powerful thing.

It's so powerful. It's powerful because we have learned over time. Your child's voice has a home in your brain, so that when we hear the sound of something that we have learned and is familiar to us, it engages again. It engages the sound mind, but engages so much of us and who we are. We all know the sound of home. When your daughter calls you, depending on how you answered the phone and your first few words, she can tell, "Mom, what's the matter?" Our voices tell us so much more than the words that we're speaking.

All of those cues create this very emotional and physical response that sound. I think that's what the book is for, all of the incredible magic that goes into having that experience, all of the biology, the science, the evolution that brings you to that moment.

Think about it evolutionarily. Mommies just needed to be able to signal to their babies that they were around. They were present even while they were busy doing other things. That's still very much the case. Babies learn right away. Even if they're not seeing mommy, they can hear. You're connected to them by your voice, by your footfalls, by the way you move. Our brains have developed for a millennia, to be able to make these kinds of connections.

By Mary Elizabeth Williams

Mary Elizabeth Williams is a senior writer for Salon and author of "A Series of Catastrophes & Miracles."

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Hearing Interview Neuroscience Nina Kraus Of Sound Mind Sound