Science Friday - How Brains Organize Smells, Plant Evolution In Art, New Hearing Aids. July 17, 2020, Part 2

Episode Date: July 18, 2020

How we smell has been a bit of a mystery to scientists. Other senses are easier to understand: For example, it’s possible to predict what a color will look like based on its wavelength. But predicting what a new molecule will smell like is more difficult. Our sense of smell can be quite complex. Take the delicious smell of morning coffee—that aroma is made up of more than 800 individual molecules. How does our brain keep track of the millions of scents that we sniff? To find out, a group of scientists gave mice different molecules to smell, and tracked what patterns were formed in their brains. Their results were recently published in the journal Nature. Neurobiologist Robert Datta, one of the authors on that study, joins Ira to discuss how our brains make patterns every time we sniff, and how wine aficionados train their noses to decode the different scents in wine. To understand variation in living things, scientists often compare specimens, recording the details. This kind of scientific investigation has long been practiced: Charles Darwin, for example, made sketches of everything from finch beaks to barnacles shells in his field notebooks. Today, natural history museums store these catalogues in shelves and drawers of preserved specimens. But scientists can also draw from less likely forums. Recently, one team of researchers—an art historian and a plant biologist—documented the different plant species represented in historical paintings and sculptures. Their results were published in the journal Trends in Plant Science. Plant biologist Ive de Smet and art historian David Vergauwen discuss what a 17th century painting by Giovanni Stanchi can reveal about watermelon evolution, as well as other trends in strawberries, potatoes, and other plants spotted in works of art. Have you ever met a friend for dinner at a restaurant, only to have trouble hearing each other talk over the din of other diners? And as we get older, this phenomenon only gets worse and can be compounded by age-related hearing loss and conditions like tinnitus. Unfortunately there is no silver bullet for tinnitus or other forms of hearing loss, and researchers don’t even understand all the ways in which the auditory system can go awry. But we now have more sophisticated technology to help us cope with it.  Nowadays, there are over-the-counter hearing aids and assistive listening devices that connect with your smartphone. Certain tech allows you to amplify softer sounds and cancel out the noise of a crowded room—it can even focus on the sound waves created by the person you’re speaking with.  Ira chats with David Owen, New Yorker staff writer and author of the new book Volume Control: Hearing in a Deafening World about the industry that’s helping millions of Americans cope with hearing loss. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Iroflato. Our sense of spell is a bit of mystery, is it not? Even for scientists, we know what a color will look like based on its wavelength. Every color has a predictable signature. But predicting the smell of something, whoa, that's a bit more difficult. For example, think of a sea breeze smelling candle. Does it really smell like the sea? I mean, how can the ocean be in a candle? But once you sniff that candle, You are transported to the coastline and that wafting breeze, yes. How does our brain keep track and organize the millions of scents that we sniff? That's what a group of scientists wanted to find out.

They gave mice molecules to smell and tracked what patterns were formed in the brain. There were results were published in the journal Nature, and here to talk about it is one of the authors on that study. Robert Data, he's an assistant professor in the Department of Neurobiology at Harvard Med School, joining us to talk more about how we sniff out smells. Welcome to Science Friday. Hi, how are you?

So tell us why has the sense of smell been so elusive to scientists? There's a couple of reasons. One is that smells are really, really complicated. If you think about the odors that are coming off your morning coffee, that scent is actually made up of more than 800 separate individual molecules.

And somehow your nose recognizes all of those different molecules, and your brain synthesizes that into the delicious smell of coffee in the morning. And so because of the complexity of odors themselves, for a long time, there have been challenges in our understanding how the brain might organize information about different odors, makes sense of them. That is really cool. You were studying mice and you gave them some odor molecules. Give me an idea of what you were looking for in the brain afterwards. So we do experiments where we use microscopes to look at neural activity in a part of the brain that's responsible for processing

information about smells. And it's part of the brain called a pyriform cortex. We as humans have a from cortex just like the mice. And we were looking to see what different patterns of activity emerge as we gave these mice different kinds of smells. And is there a definite pattern of activity? And is it located in a certain part of the brain? Yes, there definitely is. You know, our goal in this study was to answer two main questions. So first, we wanted to understand, you know, why is it that you and I, Ira, both think that lemon and lime are similar to each other? We both agree that lemon is different from pizza. And the second thing we wanted to understand was, why is it that smell seems to be so personal? Why do we, what do I think that the way that I

interact with the odor world might be a little bit different from the way that you interact with the odor world? And so the thing we wanted to look for first was whether the patterns of activity we saw in this smell center in the brain called the purifal cortex were similar in me and you. And what we discovered was that the relationships in the patterns that are evoked by similar odors themselves tend to be similar. So lemon and lime activates similar patterns of activity in my brain, and they activate similar patterns of activity in your brain. And that's why you and I both agree that lemon and lime are two similar odors. But if we expose a mouse to different odors, we can actually change the relationships between patterns

of activity that we observe in the brain. And we can change the way that animals, receive those odors. And so although you and I both agree that lemon and the line are similar, based on our odor experience, the way that we've interacted with odors in the world, our brain is clearly flexible and plastic and capable of changing the way that it represents information about odor relationships to support our perception of different odors. You know, this is all interesting because we all have a time where it could be 10, 20, 30, who knows how many years later, where suddenly you smell something

you haven't smelled for decades, and then this memory just comes right out. What's going on there? Yeah, so one of the interesting things about smell is that it was the first sense really to evolve. It's the most ancient sense we have as mammals. And so the neural circuits that are responsible for processing smell are organized

in a very different way from those of the other senses. So if you were to ask me, how many neural connections does it take to get from your retina when you see something to a part of your brain that's involved in memory like the hippocampus? That number is really large. It's like 10 or 20 interconnections between your eyeball and a part of your brain that's responsible for memory or say emotion. In olfaction, that number is two. So information about smells goes to your nose. There's one kind of processing station in your brain called the olfactory bulb, and then immediately it goes to parts of your brain involved in memory,

like the hippocampus, or involved in emotion like the amygdala. And so there's this very intimate brain connection between smells in the world and your emotional responses to those smells and your memories that are also associated with those smells and when you experience those smells. And part of the reason why my life is so fascinated with the smell is because of this really intimate connection between these emotional and memory centers in your brain and the world of smells around us. How do you train somebody to know what something should smell like or shouldn't?

So there's really two parts to this process. One is gaining language for describing what you're smelling. You know, we as humans, depending on our culture, use very different language to describe different kinds of smells. And the parts of our brain that are responsible for generating language are actually very far separated from our noses, unlike our centers for emotion memory. So although when you smell a scent from your mom's kitchen, you can evoke this deep memory,

you'll often have trouble finding the words to describe what you're smelling. And so part of what training gives you is just language to accurately describe what you're perceiving. But it's also quite clear that as you gain more and more experience with odors, your olfactory circuits are quite plastic, and they will readily learn to better discriminate and categorize odors. It's actually part of what our paper's about is thinking about how odor circuits discriminate and categorize others.

And it's clear that the olfactory system is really wonderful at addressing both of those questions and those problems and is capable of learning based upon experience. Well, then tell me, I'm bringing this back to where I started about light. If we know this certain frequency or wavelength of light, we can create the exact color we want. Can we do that with smells? Can you put a molecule together that gives you the exact smell that you want? You're asking a fabulous question, and this is really a long-standing dream of people who are

interested in the olfactory system. Wouldn't it be marvelous if we knew enough that we could construct an artificial molecule and before even smelling it, know what it was going to smell like? This is something that's not yet possible. We're just beginning to learn how chemical structures relate to patterns of neural activity in the brain, which is, of course, part of what our study was about. And understanding that relationship, understanding how chemistry evokes different patterns in your brain is really the first step towards building some sort of machine that will allow you to predict

what a specific filter chemical will smell like. And you can imagine that if you could build such a machine, it would be amazing in terms of helping people make taste your food. or more attractive fragrances. And it will also allow you to virtualize smell. You can imagine that instead of just having a virtual reality being visual, you could have olfactory virtual reality, where there were machines that were in front of you

that would spit out chemicals that you would smell in real time that would evoke various known odor percepts. Aromatherapy. Exactly, exactly. So I'm imagining there must be some connection between our taste buds, what we taste and what we smell, because, you know, the old sauce says that what you're really tasting, you're doing a lot of smelling. So is it wired into your brain that way, too?

Yeah, so flavor is thought to be the combination of smelling taste. And when you chew food up, the food gets kind of mushed up in your mouth. And then odors release from the food, and you detect those odors to something called retronasal olfaction. That is, the stuff that's coming off of your food goes up into the back of your nose and you smell it. And your brain then synthesizes information from your taste buds and from your olfactory neurons in your nose in a part of your brain called the insula to create perceptions of flavor. So those two things are really intimately linked. And if you lose your sense of smell, as you know, all of a sudden, the flavoring your food disappears.

That's what happens when you get a cold. Well, that brings me to the question about what's going on with COVID-19 and losing smell. How are these things related? Right. So it turns out my laboratory is also recently published a paper along with an international consortium or researchers exploring how it is that COVID might affect your sense of smell. As I've just told you, you know, odors in your nose are detected by these olfactory receptor neurons that express odor receptors, and these receptors interact with odors.

and then these neurons alert your brain to what you're smelling at any given moment in time. And so I think we and many others started with a hypothesis, maybe the virus infects these olfactory sensory neurons and damages them or kills them in some way. And that's how when you get COVID, you'll lose your sense of smell. But the emerging data from our lab and the labs of our many collaborators really suggest that instead what's probably going on is that the novel coronavirus, is infecting support cells that live around these olfactory sensory neurons. And so somehow through infecting these support cells,

your neurons in your nose stop functioning properly, and so you can't smell odors anymore. And we actually think this is pretty good news because it suggests that people with COVID who lose their sense of smell will eventually regain their sense of smell once these support cells kind of regenerate and heal. That is good news. As someone who is whose job and sounds like passion is sleuthing and smelling everything, smelling all the roses along the way, do you drive people crazy, stopping to smell stuff?

I do. Especially when I go to, when I go shopping, I cannot stay away from the perfume counter. Some of my favorite moments are discovering new smells just out in the environment. It's fun to study a sense that I find really personally very satisfactory. You know, in science, this is called me-search. You do research on the thing that you yourself find most interesting. And for me, this has definitely been quite a bit of research. Well, that's great that you enjoy it. And maybe someday one of these perfume companies will name something, Data after you.

Never know. Thank you, Robert. Robert Data is one of the authors of a study in nature about spells. He's also assistant professor in the Department of Neurobiology at Harvard Med School. And I want to thank you for taking time to be with us today. Thank you very much. I'm Ira Flato. This is Science Friday from WNYC Studios.

This is Science Friday. I'm Ira Flato. You know, in science, if you want to understand variations and living things, you take a close look at them and you catalog the details of what you see. For example, in his field notebooks, Charles Darwin, and made sketches of everything from finchbeaks to barnacle shells, natural history museums, catalogues, shelves, and drawers of preserved specimens. And now there's even one team of researchers looking at works of art.

They're looking how different plant species are represented in paintings and sculptures. Producer Alexa Lim has more. When you visit a museum, you've probably run across a still-life painting. Usually, the image is filled with commonplace objects. maybe a vase with a bouquet of flowers, or cups overturned with fruits cascading across the table. And when you step in for a closer look, you might think to yourself,

is that a strange-looking apple? Or maybe it's an orange? Well, you're not alone. A plant biologist and an art historian have teamed up to catalog the fruits and vegetables and works of art. They're looking at details in these paintings and sculptures as a way to figure out the evolutionary history

of some of these plants. Their results were published in the digital Journal Trends in Plant Science. Eve de Smit is a plant biologist at VIB Ghent University's Center for Plant Systems Biology, and David Vergawan is a lecture in cultural history at Amarant. They're both authors on that study and joining from Ghent Belgium. Welcome. Happy to be here.

Thank you. So, Eve, as a plant biologist, you use genetics to study plant development. You have a lot of technical, scientific tools. So why I look at art, what can that fill in that maybe molecular biology camp? Well, in a way, because it's fun, this is kind of an out-of-hand hobby project between David and myself. And what we try to do with the kind of molecular component here is we are really trying to explain why certain differences are what they are. So what we observe on a painting, certain phenotype, certain features of color, shape, size, and these kind of things, can we find some molecular explanation for those components? And with all the knowledge we have nowadays on how plants grow the kind of metabolic pathways

that are involved in generating color and taste and these kind of things. So we know the key individual players for that. We can actually try to use that information to really find a good explanation. And David, on your end, artists aren't always making exact representations of what they're saying. So how do you weed out the information from what I'm going to call the artistic license? Well, that is a fundamental problem when tackling this sort of research. Artists can be quite fanciful, and it is the job or my job as an artist-oriented to make sure that the information that we collect from these paintings, these objects of art, that they are in some way representational for our study. So that means finding out or finding a method to really know what is reliable and what is not.

For example, if you look at a painting from 16th or 17th century Dutch painters or Flemish painters, how can you really know that in a market scene the fruit and vegetables that are depicted are really as they were at the time? Because some of these combinations seem quite odd because they don't grow in the same season and probably weren't put up for sale at the same time. So what we then do is we look at other things. So you can look at the clothes people are wearing or you can look at the clothes people are wearing, at the architecture, if there is architecture on a painting and you can visit that actual place and the architecture is still there and you can cross-reference the existing place with the painting.

Or you can look at musical instruments if they're on the painting and you can go to a museum and check out those musical instruments. And that is the way how we can double check and cross-check the validity of the things that we are observing on a painting. And this whole project was kicked off by a painting of a melon. Can you tell me how that happened? That is a funny anecdote. We've been friends for way back, and every once and a while we get the permission of our wives to go and visit the city that they don't want to visit. And we found ourselves in Russia in St. Petersburg at the Hermitage with a painting by Franz Schneider, a Flemish painter from the 17th century.

We were discussing whether or not the melon that was depicted on that painting was, in fact, the way it used to look. So I asked Steve, is this the way a melon looked in the 17th century? And he said, well, maybe it's just a bad painter. And then I said, no, no, this is Francaves. He's a really good painter. He's a very reliable in that case. So then we kind of started to take out our mobile phones and look for references and scholars and articles

that might have some sort of indication of what was going on. And we quickly discovered that there were not that many people who were interested in cross-referencing art history with genetics. And that's how we started talking. Basically what was shown was a watermelon cut in half and it was white on the inside, which is a bit unusual, no, because if you think of a watermelon, everybody recognizes the outside as having this dark green, stripy pattern, so alternating dark and pale green. and on the inside, if you cut it in half, it's really dark red. So the one that was depicted there was white. Are you confident to say this is a watermelon?

There are a number of possibilities there. So there are other examples. So there is a nice example from an Italian painter, Stanchi, who also paints a strange-looking watermelon when cut in half. So it's a bit more white, pinkish, with this kind of weird swirls on the inside. And then, of course, you can discuss, is this now a watermelon that was, not fully matured, is there a watermelon that was grown in conditions where it was deprived of, for example, water or nutrients or something like that? Or is this really a mature watermelon as it

existed? And there are a number of botanical elements that you can consider for that. So if you look at the ripening process of the watermelon, it indeed starts off as being white, and then it kind of goes to this stages of turning pink until it finally becomes really red. And when it's becoming red, the seeds, the mature seeds are black in color. So you really know dark red together with black colored seeds is a mature watermelon. If you go and look at an immature stage, then you see that it's either white or pink and then the seeds are whitish in color. So then it's not fully developed. The way both Stanchian and Snard is depicted is essentially a watermelon, which is white or pale, pinkish in color, but with black seeds, really indicating that it is

probably mature watermelon, which doesn't mean that at the time the red-fleshed watermelon did not exist. So probably both varieties coexisted at some point, because if we look into this genetic evidence of this watermelon from 3,500 years ago, from old Egypt, we do see that at the time the red-fleshed watermelon probably already existed. So the sweet-tasting red-fleshed watermelon occurred already 2,500 years ago. You've also looked outside of Europe, and one example is the potato. What's the story behind that? Well, the story about potato is extremely interesting because the potato was a crop originated from

South America, of course, which sustained civilizations like the mocha, for whom this potato was very important. and it figures quite predominantly in their pottery, which has a lot of these small characters, kind of humanoid looking, and they are made out of potatoes because you can actually see the eyes of the potato that are molded into the sculpture.

And you can find this kind of pottery not only with the mocha, but also all the way down to the Urpuss-style Inca pottery. And it goes to show, how important it was as a calorie source for these civilizations. And it is probably also related with the downfall of the moche by the hand of their more powerful neighbors, the Tibanaku, who once they conquered the region around Lake Titicaca,

really controls the potato trade at that time. But the interesting bit to note is that even though the potato was quite known in Europe in the 16th century, It wasn't really eaten in any significant amount, wasn't really adopted in any culinary practice before the middle of the 18th century. So there is kind of a time lag between the discovery of this potato and the actual adoption in the kitchen. And this is quite astonishing since, for example, the Inca, they had stability of food sources, not only with the potato, but also with mice, the corn coming in from Mexico, so they have two calorie sources that are quite efficient. Whilst in Europe, we only had the wheat.

So we only had this one calorie source, and the introduction of the potato really introduced some sort of food stability. And I guess what I'm trying to say is that this story about looking at paintings and finding out the genetics and telling the story of the evolution and the travels really involves the story of the rise and fall, of civilization, of exploration, of cultural adoption, culinary practices, and so on. So it is really the story about how humankind molded its food into its own needs. There are often a number of misconceptions.

So typically the potato was feared in a way because it's a member of the nightshade family, the Solomacy. And then members of this family are typically poisonous. So that's why people didn't really like to eat those types of fruits and vegetables. So they have the potato. The tomato has a similar association. It's kind of this gild by association that kind of caused that these fruits and vegetables were not really popular at the time.

So is there like a different representation of the potato in Europe then? Or do you know when at first, like the first image of a potato happened? But the first really depicted potato associated with the time that it arrived in Europe, we haven't spotted that one yet. So I think we have a few examples. We have mentions in the literature. This is one of the things that we still would like to explore

in a little bit more detail. So when do we start? So how often is the potato depicted? So we don't have a very good overview of that. We do have it with a tomato. And that's also interesting because you were just explaining that they were killed by association and a bit feared at the time for various reasons.

The interesting bit is that when the tomato is introduced in southern Spain, it takes about 70 or 80 years before it appears on a painting by, I believe, it is Murillo, who has this famous kitchen scene and actually depicts a tomato. And then you can look into the past to see what it was shaped like. And it was a red kind of kerdubuff-style tomato. And these things are quite valuable, then you can have descriptions or you can have botanical drawings, but if you can see it with full shapes and colors,

just lying around an early 17th century kitchen, that's really spectacular. So if we could find something like that with a potato one there, then we'd be very happy. Wow, a potato mystery. Are there plants that seem to be painted and represented consistently? As far as we've noticed, I think the onion is one example. where we see very little variation.

Also with respect to, I think, apples and things like that, cherries, grapes. You have a lot of diversity, but that's clearly captured, so you can really see this kind of enormous diversity of apples. But it always looked like an apple, so it's not kind of an unusual depiction that we spotted, something like that. Same with grapes, no, that's also something. And onions are the same. They're always recognizable.

as an onion as far as we've seen so far. So are we talking about the bulb of an onion or the stock? It's the bulb of an onion. Okay, yeah, yeah, not the stock. It's really the bulbous part of the onion. You all are focusing on fruits and vegetables but plants in general. I mean, how else could this be applied? We're not going to do this for cattle.

We're not going to do this for regular flowers and things like that. So really kind of try to define a niche. Although it can be applied to all these other things as well. I mean, you can also look at butterflies and at lichens and basically conclude or draw conclusions with respect to pollution at the time, but really kind of try to define our niche about around plant-based foods, essentially. But that's the nice thing. I mean, these painters are able to paint something

which is kind of photographic quality. so you can really rely on a lot of these artists to draw conclusions based on what they depicted. I'm Alexa Lim, and this is Science Friday from WNYC Studios. David, did you ever think you'd be critically looking at apples and pairs? Not in my life. So I was kind of dragged into it because it might be surprising to know that I am not really that into biology. I've always wondered why Eve went off to study biology. But it brought us a bit more together as friends, I think,

and working together has been tremendously big fun. So I have learned a lot and more than I have ever thought about genetics and plants and fruits. And you can't imagine. There is some miscommunication. There are certain species, names and things like that that David refuses to pronounce or to name correctly. And I'm terrible with years. I don't know when I'm. a certain painter lived and worked and these kind of things.

I guess on that note, you're asking for help from people. So what do you want them to do? Well, we can be at all museums at the same time. We cannot visit. I mean, there's not enough time for us to look at physically every painting that might be interesting. So we are just asking the public to help us, to assist us in a very simple way. if you are in a museum and hopefully a museum that is not that well visited, maybe obscure collections or it can be a big museum where there is just one detail that you're focusing on.

Well, take a picture. Take a picture of the fruit or the vegetable that you find interesting, a weirdly shaped carrot or an odd-looking onion. We are interested. Take a picture of the detail. Take a picture of the painting. and please don't forget to take a picture of the little sign next to the painting indicating what it is that we are looking at.

It might be more spectacular, if you find the potato from it on a 13th century European painting that might completely change our view on trading routes and conquest and discoveries. So these things could be really interesting. And the important bit is that when you have taken these pictures and collected all this information, you can just email it to us to Art Genetics, David, Eve at gmail.com, and then we try to do something with that.

And we also have the Art Genetics hashtag, yes. Thanks so much for joining us. You're welcome. Cheers. Eve de Smit is a plant biologist at Vib Ghent University's Center for Plant Systems Biology, and David Vergowan is an art historian at Amarant in Ghent, Belgium. And if you want to help with their catalog, you can tweet your photo out with a hashtag Art Genetics. And you can see images of the works of art up on our website at Science Friday.com. For Science Friday, I'm Alexa Lim.

After the break, the world is getting louder as your hearing suffered. We'll talk about hidden hearing loss, what's next in hearing assistance technology, and why prevention is still your best cure. So coming up after the break, stay with us. We'll be right back. This is Science Friday. I'm Ira Flato. Imagine that you and I are sitting across the table from each other at a crowded restaurant, just a couple of old friends catching up. What?

Can you say that? What did you say? Sorry, I really can't hear you. Does that happen to you, right? It's common. You have trouble making out words. You're not alone. You're in a restaurant.

All that background noise gets in the way. If you're a member of the baby boomer generation like I am, that scene may feel pretty familiar, especially if you have a tinnitus in one ear, or both ears I have in one ear. Unfortunately, there is no silver bullet for tinnitus or other forms of hearing loss that come with age, and researchers don't even understand all the ways

in which the auditory system can go awry. But we now have more sophisticated technology to help us cope with it. These days, there are over-the-counter hearing aids and assistive listening devices that connect, for example, with your smartphone. Tech that lets you amplify softer sounds or cancel out the noise of a crowded room. Even zoom in on the sound waves created by the person you're speaking with. And in fact, so much has changed about the industry catering to people with hearing loss that my next guest wrote a whole book about it. David Owen is a New Yorker staff writer and author of the New Yorker.

book Volume Control, Hearing in a deafening world, which is out now. David, welcome back to Science Friday. Hi, Ira, thank you. That restaurant gave me the chills. Isn't that really familiar, right? When I was working on this book, I talked to people, go, ask friends, how's your hearing? How's your hearing? Oh, it's pretty good.

They go, you know, except in restaurants. And it makes a big impression on people. And isn't that one of the first symptoms of having a hearing loss is that you keep saying what? Yes. I didn't hear it. Say that again? Right? Yes. And unfortunately, the average wait time between noticing that you have a hearing problem or suspecting that you have one and actually doing something about it is 10 years. That's the average that people wait. Is that because they think they can just plow through it or that they can't be having a hearing loss? I think there are a number of reasons. I think one is that we don't take hearing anywhere near as seriously as we should. We don't realize how important it is in our lives.

Another is just, you know, sort of good old human inertia. And another is it kind of the stigma, the perceived stigma of having hearing aids. It's a sign of decrepitude, hearing loss. There was Charlie Rose, back when he was on TV, did an hour-long show on hearing and hearing loss. And during that whole time, he never mentioned that he was wearing hearing aids. He had two hearing aids on. And one of his guests, who was a Nobel Prize winning physicist, you could see his hearing aids. And he also never brought it up.

So there's some feeling that it's somehow shameful or embarrassing to do something to help your hearing. Yeah, and something that comes along with hearing loss is, as I mentioned in the intro, that I have a tinnitus ringing in my ear. One of my ears is my right ear, and that compounds the problem. Yeah, I have it too, and I've discovered that one of the very worst things you can do for tinnitus is to write a book about it because then you're thinking about it all the time. And unfortunately, there's no known cure treating it mostly involves helping people learn to just to tolerate it or to mask it with other sounds or to sort of make it less apparent by prescribing hearing aids to bring up the sound of other things so that the tenetis is less apparent. But it's a, it's, and it is the number one service-related health claim made by military veterans. It's soldiers from Iraq and Afghanistan and then back through every war that we've fought since the Civil War. It's been a problem for soldiers.

Because if you have a rifle on your shoulder and you fire it, it's a loud boom. That's right. Right-handed infantrymen tend to go deaf on the left side. That's the ear that's the closest to it. And then it happens in surprising places, too. Violinists lose hearing in exactly the same way in the left ear. We don't think of symphony orchestras as being harmful to hearing. It tend to think of like heavy metal rock, but classical musicians are prone to it too.

And it's often not your instrument. It's the instrument of the person sitting behind you. So it's the French horn right at your head in the chair in back of you. You know, speaking personally, you don't really, you know, the old saying, you don't know what you've got until it's gone. Because I'm almost deaf in one ear, I try to make sure I protect my other ear. from any kinds of loud sounds. And living in New York City, walking down the street, you know, I really find myself cupping my ear,

closing it off, putting my finger in it when a truck or something goes by. And a lot of people are just not doing that kind of thing, and we're exposed to loud sounds all the time that may be harmful. Oh, it's so true. You know, it's just watching a football game over the weekend. And the commentators were talking about how enthusiastic the fans are. The sound of the cheering is so loud, the linemen can't hear the quarterback calling signal.

the quarterback calling signals, and they actually gave a decibel reading, and it was well above the level that can, you know, with sufficient enough exposure can cause permanent hearing loss. And it's, you know, it's not a good thing to be this enthusiastic with this many people. It's not good for your ears. You know, but the good news about this now is that we have cell phones and electronic devices that might make up for some of the shortcomings we have with hearing loss. For example, I discovered, because I know so many people who have hearing aids, that hearing aids can now be hooked on to your cell phone, on your iPhone, for example. You can hook it right on there, and then you can sort of slide your cell phone across the table, and act sort of like a remote microphone going to your hearing aid.

That's right. They're very expensive devices that do the same thing, but you can do that. I got my mother's 90. She's had trouble with her hearing. She's been reluctant to go and get hearing aid. So I bought her, I think I spent $80, a device called Super Ear. It is a little unit that's maybe the size of a, you know, smaller than a cigarette, a pack of cigarettes.

It hooks to a wired pair of earphones, and she can adjust it and place it on the table. You know, all she has to be to do is be willing to have this visible sign that she's not hearing. But she did take it to dinner with some friends, and they passed it around. And I've done the same thing with more sophisticated devices. You know, go to a sports bar. I have a pair of headphones called hearphones made by Bose. And they're basically, they have the same chip that hearing aids do, but they have a bigger battery, so they have better Bluetooth.

They have bigger speakers, so the sound is better. They have noise canceling inside the ear canal as well as outside. So you can, in a restaurant, if we had been in that, that situation at the beginning of the segment, I could have turned down the sound of the restaurant and focused on you specifically without putting my phone on the table. And, you know, we would have had an easier time talking. That's great to hear. Are there any treatments? Because if you, you know, of a certain age, you hear on TV, you watch commercials that say, oh, there's this miracle cure for tinnitus, you know? Right. But there is no such thing, is there?

No, and you search for it once on Google, and your email inbox fills up with all these claims of, you know, the food you should eat, you know, this thing that doctors don't want you to know. Don't let the American Medical Association know that you know about this. Unfortunately, they don't work. There's some things that people find that help them. One, surprisingly, something that sometimes helps me is to simply pretend that my tinnitus, this high-pitched sound, phantom sound in my head, is a masking sound that I'm playing to cover. up my tenetus, and that doesn't always work, but sometimes it does. I'll turn on a fan, turn on the air conditioner. I have some earpieces that actually play a masking sound, and they help, too. Yeah, some people will put their white noise machine on it at night. Right, exactly. And you can get something that's sort of in the kind of covers it. I've walked in places where the traffic noise, just kind of steady hum from an interstate

highway, was right in the right frequency range. to make me unable to hear my tenetis, or in the fall with cicadas and crickets, that's kind of in the same range, and then I hear only them, I don't hear this phantom noise in my brain that usually I only notice when I'm lying in bed or writing about it.

Yeah. The new research on tenetis suggests that it's something like phantom limb pain, right? It's not there, but you still feel it. I think this is beginning to be, being, is the accepted idea now. Your brain is used to receiving signals in certain frequency ranges. Now you've lost the ability to hear those ranges, and so it makes its best guess about what ought to be there. It fills something in. And so there are some treatments that work with some

people that involve kind of training the brain to ignore that entire frequency range. Tenet's is tricky because it's not a sound. It's not sound waves coming into your head. It's an electrical activity taking place in your brain. So people at Bose are always asked, well, can't you make noise-canceling headphones that will take care of this? And they say, no, we need, in order to cancel sound, we need sound, and you don't have sound. This is something else. But, you know, there's hope. There's always hope. Yeah. You mentioned Bose, and I think about this a lot. Why doesn't Bose or Apple or somebody go into the hearing aid business that they know all about sounds, they make all these phones and they make the headphones and you know there's a whole bunch of baby boomers and

people who are youngsters who are going getting deaf from all the loud music they're playing this would seem like a great business model you know no it seemed that way to them and people suggest it all the time and Bose actually now has been approved for a hearing aid there's there will be a hearing aid coming from Bose and my my Bose hear phones these headphones they function they can't legally call them hearing aids but I can I mean they're hearing aids that I like better than hearing aids. One reason that these companies have not been involved fully yet is that it's really hard to make a hearing aid. And they all thought, well, we have the expertise, we'll get into it. But the processor inside a hearing aid, the circuitry inside a hearing

aid, the antennas, it is tiny and it had to be invented by the hearing aid industry because there is nothing off the shelf that works. And so Apple has a partnership with a hearing aid manufacturer, but it took it took them years to do what they thought they would be able to do just, you know, immediately based on what they already knew. And they've all discovered that it's much harder than they thought it would be. You know, I always think that there's going to be new research coming out by the Pentagon. The Pentagon spends so much money, has so many soldiers that are in combat and all kinds of suffering all kinds of losses. And from reading in your book, it seems like they know about, as you say, one of the, the number one injuries in combat is loss of hearing or tenetous, and they have a way of

getting, of combating that? You know, it's interesting. Military personnel, we have known for literally for centuries that warfare is bad for hearing, that gunfire defends people, that artillery fire, that simply being around, you know, in military equipment, military vehicles, defends people. But it's really only in the past few years that the Pentagon has begun to use truly effective hearing protection devices. There are hundreds of pending lawsuits right at the moment over what were supposed to be protective earplugs that were issued to soldiers in Iraq and Afghanistan.

They were defective. They didn't work. The Pentagon knew they were defective. The manufacturing knew they were defective. And you think, you know, we knew at the end, we knew during the Civil War. We knew before that. We knew in the age of sale that exposure to explosions deafens people. And yet the focus has always been more on compensation than on prevention. So, you know, the Veterans Administration is the largest single purchaser of hearing aids in the United States.

But much more money has gone into that than has gone into research to protect the hearing of soldiers. Amara Flato, this is Science Friday from WNYC Studios. Talking with David Owen, New York staff writer and author of the new book Volume Control Hearing in a deafening world. Great book, especially for, you know, if you think you may have a don't want to admit that you have a hearing problem. And the title is really indicative of the state we are. We are in a deafening world. There are so many loud things around there. And we have a tweet from David who says,

there are also some nice decibel meters available online to improve your awareness. That's true. I have one in my cell phone has a DB meter that I use. Yeah, one of the difficulties with decibels is that even scientists who understand them have a hard time explaining them. The scale is logarithmic. It's not so 90 decibels is not just a little bit louder than 80 decibels. It's a lot louder. And the, the, I think, I came up with a scale of my own, which is, you know, things like whisper, soft voice, chainsaw, rock concert.

More items that, more items that we're more familiar with than we are with these numbers that we don't really, that are very hard to understand. The basic takeaway, though, is that we are exposed constantly, especially somebody, you know, living in a big city, but really everywhere, to let really loud sounds. that can hurt our hearing. You know what the loudest sound I, you know, because I'm, what I do for a living is listen, the loudest, most annoying sound I have found recently and I actually brought my decibel meter to check it out was in an airline, the airline bathroom.

When you flush that airline toilet, it's over 100 dB. That's loud. And it peaks out there. People thought I was crazy. Yeah. Federal regulations are sounds that are close to painful, are certainly damaging, that workers in covered industries are allowed to be exposed to for, you know, eight hours a day,

five days a week, 50 weeks a year. And even the government knows that what regulations we have are not sufficient to protect those people. It was also, I was thinking one of the threats to the health of marine mammals is human-generated sound. We, the, the largest single input of human generated sound into the oceans is shipping, ocean shipping, the sound of the engines and ships. But we also, you know, we explore for gas and oil by basically setting off explosions underwater than listening to the seismic echoes. All these things have devastating effects on marine life. It's marine mammals, which have ears like ours. And we don't, We don't even know what impact we're having.

Yeah, we really are not aware of how loud the sounds we are and the sounds we are making that might disturb the world we live in. That's true. And I always used to make fun of my wife because she would put on ear plugs when she used her food processor. But now I do it too. You know, she bought me, when I was working on our house, she bought me a set of protective earmuffs. And I would only put them on if I thought that she could see me. But now, you know, now I wear them all the time.

and I carry a pair of musicians' earplugs on my keychain, and I'll put them in even. You know, my wife and I went to see the movie Dunkirk, which is basically one continuous explosion from the opening credits to the end. And it made it tolerable. It was painful otherwise. Yeah, I get it, because I bring mine to weddings and bar mitzvahs. Vans are very loud. Yes, thank you very much. David Owen, New York staff writer, author of The New Book, A Great Book, Volume Control, Hearing, and a deafening world.

then we have an excerpt on our website at science friday.com slash volume. Thank you for taking time to be with us today, David. Oh, thanks, Ira. And that's about it for this hour. If you missed any part of this program or you'd like to hear it again, yeah, subscribe to our podcasts or ask your smart speaker to play Science Friday. And on Science Friday Voxpop app, here is our question. We're talking about the long-term effects of COVID-19.

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