S1 Episode 48: How Noise Affects Our Brains

Blaring music, incessant traffic, those early-morning lawn mowers — you know they’re bad for your sanity, but for your brain? Dr. Mathias Basner, an expert on the effects of noise on health, explains what goes on in your body when it’s subjected to prolonged high-decibel exposure, including irreversible hearing loss, cognitive decline, even heart attacks. Fortunately, there are some practical ways to protect yourself — and to reduce your own “noise footprint.” 

Dr. Phil Stieg: Exposure to noise is an underappreciated public health hazard. Many people understand that loud noise can affect our hearing, but few understand how dangerous it is for our heart and our brain health. I’m especially grateful to have Dr. Mathias Basner as our guest today,. He is associate professor of psychiatry at the University of Pennsylvania School of Medicine and a world renowned expert and researcher on the effects of noise on health, cognition and sleep. He has been an advisor to the World Health Organization, President of the International Commission of Biological Effects of Noise. And one of NASA’s team of research scientists who studied the effects of space on cognition.

Dr. Stieg: What percentage of the population in the United States actually has hearing difficulty?

Dr. Mathias Basner: Over 50% of US adults suffer from high frequency hearing loss in their sixties and looking at it globally, there’s 1.6 billion people are affected by hearing loss worldwide.

Dr. Stieg: And it isn’t only hearing loss, but it’s also sounds in the ear like ringing or on the other end of the spectrum, hypersensitivity to sound called hyperacusis. In addition to hearing loss, those hearing problems. Correct?

Dr. Basner: Absolutely, and you know they can really be debilitating. People that live with tinnitus, they have problems falling asleep, staying asleep, obviously and their communication and being able to concentrate on a conversation. So, yes, it’s not only hearing loss. It’s several different things that can affect our auditory system and the way we perceive our environment.

Dr. Stieg: You’re a world expert on the concept of noise. Can you define for me what really is noise?

Dr. Basner:: Well, noise, we define noise as unwanted sound as such, it has both a physical component, which is the sound level, but also like a psychological component that is, you know, really the circumstance that makes the sound unwanted. And my typical boilerplate example is the rock concert. You know, people who are at the concert, they don’t perceive the music as noise because they actually like the band that they paid a hundred dollars for the ticket. The sound levels are very high, but they don’t think of the music as noise. In contrast, you could think of somebody living three blocks away from the concert hall, trying to fall asleep or trying to read a book, they can’t do that because of the music. Although the sound levels are much lower in this situation, they still think of the music as noise and it may actually trigger processes that can, in the long term, have health consequences. So it’s really, you know, both how loud it is, sound level and what are the circumstances in which I perceive that sound.

Dr. Stieg: I presume there’s again, two spectrums. There’s this unwanted noise that we hear, but then we also frequently talk about white noise. Is that equally as bad for you?

Dr. Basner: White noise is just sound that has a certain spectral composition where people introduce a sound source or noise source. For example, in their bedroom, trying to, you know, cancel out or mask other events that are intruding into their bedroom to actually improve their sleep quality.

Dr. Stieg: And for the individual that’s really interested in protecting their hearing, there are now smartwatches that you can buy that will tell you what’s going on in the environment. So you can monitor where you are, where you’re living, where you’re working and see what you need to do about this ambient noise?

Dr. Basner: You know my friends are totally annoyed by me because I no matter where we are, I pull out my smartphone and measure the sound level and I will show them, you know, “Oh, this is way too loud.” And then they’re just rolling their eyes.

Dr. Stieg:  You’re the party crasher.

Dr. Basner: Yeah. Yeah. I’m the party pooper. Yeah. Uh, I actually did the same thing. I was at a, at a, like a pop concert with my daughter who was only 12 years old and I measured 104 decibels. And at that point I said, you know, I’m measuring this. Why can’t my phone alert me that is that it’s too loud? And I actually sent myself an email, you know, wanting to write to Apple to introduce that feature. And as always, when I have like the good idea a week later, I read this article that Apple introduced that feature into the newest version of the Apple Watch. So this watch will actually tell you, “Hey, it is too loud. You know, you should either protect your hearing or leave this environment to protect your hearing.” And I think this is very clever and we were carrying around these smartphones that basically can do everything. So why not, you know, use those as devices that alert us when we are in dangerous situations.

Dr. Stieg: Why is hearing loss so dangerous? What’s the downside?

Dr. Basner: Well, I mean, the downside is manifold. One is of course that, I mean, communication is an integral part of what we are as human beings. Actually, the very first sign of beginning hearing loss is that when you’re in crowded areas and you try to have a conversation, you really can’t do that because it gets so much harder to really understand what the opposite person is saying. And what happens in people in older age who have more pronounced hearing loss that they will actually withdraw. You know, it’s becoming a major effort to participate in conversations, trying to concentrate on the conversations that they’d rather withdraw from that. And it’s changing everything that they are in their everyday life. So that’s what makes it so debilitating in the end.

Dr. Stieg:  Yeah. Before we get into the impact of hearing loss on the individual, just wanted to talk a little bit about the mechanism of hearing loss. Is it damage to that tympanic membrane or the conduction pathways or the nerves brain damage or all of the above?

Dr. Basner: Yeah. It’s basically all of the above a little bit for the tympanic membrane to rupture, it has to be extremely loud. That’s something that we rarely see. The main mechanism is actually that the so-called hair cells that they are damaged by noise exposure that happens too often and is too loud. These are the sensing organs that basically send the, the electrical system to the brain and they can be damaged in two different ways. One is indeed physical damage. And, you know, an example that I like to give is a loud speaker. I mean, if you have a loud speaker attached to your stereo, it operates in a certain range. And if you turn up the volume too high, you may actually physically damage the loud speaker up to a point where it’s not working anymore. The same can happen with these hair cells in the inner ear. If the signal that’s coming through, it’s just too high. Then there’s physical damage to the cells. The bad thing about this is that hair cell loss is irreversible. That is, you know, once that cell is dead, you know, it won’t come back, hearing loss is permanent. And right now there’s really nothing we can do to recover these damaged cells.

Dr. Stieg: I wanted to get back to something you referred to earlier about the withdrawal. Let’s face it, hearing loss is more common in the age population. So the person becomes isolated. What can that do and is there any data that suggests that hearing loss accelerates dementing processes or diminishment of cognitive skills?

Dr. Basner: Yeah, there is actually evidence emerging and this that, you know, there’s more and more epidemiologic studies finding that those people who do have a verified hearing loss, that they’re also more likely to show a cognitive decline. And I think the proposed mechanism is, again, you know, you, you have a hard time understanding. So you have to basically devote a lot of cognitive resources to just this adorable process of understanding and hearing typically that’s something that, that happens, you know, subconsciously in the background, but now you have to, you know, reallocate these resources to that process. And that may be one contributing factor. I think there’s still a lot that needs to be done. This research is still in the, in the very early stages, but there is good plausibility that the hearing goes, could be causally related to cognitive decline that some of these studies see.

Dr. Stieg:  We certainly know that individuals that spend more alone time and have less interpersonal interactions have a more rapid decline. So common sense would prevail that avoiding hearing deficits would be to their benefit. I’m also surprised to see that the number one cause for workman’s comp applications is hearing loss, which would mean that it’s actually affecting middle aged and even younger people.

Dr. Basner: Once your workplace exceeds a certain noise level, you’re actually mandated to wear hearing protection. You know what, oftentimes, and again, I’m a keen observer of this, you know, I see a workers mowing lawns or blowing leaves. And oftentimes I don’t see this hearing protection. People are just not using it, not wearing it. That’s the reason why this is the number one cause for, for workers compensation,

Dr. Stieg: When people experience hearing loss, what are their options to either fix it or an alternative form to enhance what they’ve already got?

Dr. Basner: At least right now, there’s very little we can do in terms of the root cause. You know, these, these damaged , hair cells of the ear. The most obvious thing is getting a hearing aid. Basically what that will do is it will enhance sound levels in those frequency ranges, where you have hearing loss and that will make it possible for you to regain some of that function that was lost due to the hair cell damage.

Dr. Stieg: And there’s a lot of stigma about having hearing aids. But I think that we should try to alleviate that. The devices that are in existence now are really minuscule, not visible to the people around you. Are there noise, canceling hearing aids, so it really helps enhance what you, what you’re hearing?

Dr. Basner: Yeah. I mean, absolutely. They’re, they’re becoming really cool devices. A colleague of mine actually just got hearing aids. Actually, I prompted him to have his hearing investigated. And first of all, as you said, you can’t really see them anymore. They’re tiny, but he’s also taking phone calls on them. So they basically double up as, headsets, invisible headsets. So you can listen to music over that and we can take phone calls and then they have that very important function that he can hear properly what’s going on in his environment. I think that the bigger problem is really, you know, especially the United States, giving large parts of the population access to these hearing aids. And obviously there’s a range of qualities. You know, you can have like very simple devices that probably don’t work as satisfactory and you can have more expensive devices that work much better. So again, it’s kind of like social justice problem that people probably have worked in very loud occupations who have the problem now can’t afford proper hearing aids. So this is definitely something that we, as a society need to work on to, to alleviate the symptoms of hearing loss.

Dr. Stieg: Mathias, can you specifically tell me how noise affects the heart?

Dr. Basner: Yeah, noise is basically a stress, and it triggers reactions in our bodies. For example, the excretion of stress hormones like adrenaline and cortisol that, lead to changes in the composition of our blood and in, in changes of the structure of our blood vessels, which have been shown to actually be stiffer after a single night of noise exposure. But there’s a number of epidemiological studies showing that people who have been exposed to relevant noise levels for a prolonged period of time, that they have a higher risk for cardiovascular disease like heart attacks, high blood pressure and stroke. And although the risk increases are relatively small, like only a few percent for a 10 DB increase in noise levels, it’s still a major public health problem because so many people are affected, by relevant noise levels,

Dr. Stieg: Probably the best way to treat this is to avoid the problem. Can you give me five quick things so that I can avoid hearing loss when I get older?

Dr. Basner: One thing that I always say when I hear this question is, you know, we’re not only noise recipients, we also know noise producers. So very much like a carbon footprint, we also have a noise footprint. We really should try to reduce that. That is, you know, don’t start mowing your lawn at 7:00 AM on a Saturday morning because all your neighbors are still sleeping. Try to be respectful and try to produce as little noise as possible. And of course we can protect ourselves against the noise. A couple of things that you can do are first of all, really, you know, you need to speak up if, if you’re in a cinema and it’s way too loud, complain about it. If nothing is done, just leave . Demand a refund of your money because it’s really not worth losing your hearing over this one movie and typically demanding back your money, that’s a language that the owners of the theater will understand. The same is true in a school environment. Often see that, you know, there’s a, an event at the school and they have a DJ. The DJ is of course deaf already., And it’s way too loud. So I will walk up to the DJ and tell them, you know, turn it down. And actually, you know, listening to loud music is pleasant, but if it’s way too loud, it’s actually not pleasant anymore. You can’t have a normal conversation. So, you know, speak up. And if nothing happens, leave that environment because your hearing is much more important than, you know, attending that event for an hour or so. You should really talk to your kids about noise and how important it is that they don’t expose themselves to levels that are too high. Noise canceling headphones, they’re a wonderful invention because we always adjust the volume to the background noise level, and this is what these headphones do. They know the background noise level, so we don’t have to expose ourselves to levels that are too high. Another thing that, of course, you know, traffic noise is a very prominent noise source, so if you’re living in the house that is close to a busy road, one thing you can try to do is move your bed bedroom to the back of the house where your own house is shielding you from the traffic noise outside, and then you get a better night’s sleep. And we know that sleep is so important for recuperation and also longterm health, including cardiovascular health. So these are all things we can do. We don’t, we should also, you know, really seek out quiet spaces. It’s getting harder and harder to find these spaces with, with ever increasing noise, but we should really try to seek them out and, you know, basically allow our system to wind down and recuperate from all the noise stress that we’re constantly exposed to.

Dr. Stieg: I have to ask you the question, I have a country house and when I have friends that come out there from the city. They actually seem to have a rebound effect. They say that it’s too quiet. I can’t sleep.

Dr. Basner: Yeah, it’s true. I mean, I guess. We as humans, habituate to our conditions, and also to noise, I mean, we ourselves have run studies in the laboratory where we expose people to noise during sleep. And, you know, during the later study nights, they will wake up with a much lower probability that at the beginning, that is biologically, you know, sensitive reaction of the body, but we never habituate fully. But the same is true, you know, when you, it’s just changing environments, like if I go to New York City, I say, “Oh my God, this is super loud. And then, you know, I can’t sleep in this loud environment. I will seek out a hotel room that is not directly facing the road, et cetera.” But people are used to that environment. If they go into super quiet environment that freaks them out. It’s just signaling the body, something is different here. Different always means potentially dangerous. And that’s why they may not be able to fall asleep. Actually I have a very nice anecdote of somebody living close to a rail track. And, you know, that person participated in one of our new laboratory studies and reported that there’s typically a 5:00 AM train and, you know, one time that train wasn’t coming in and he was waking up because it was coming because again, it was unusual, right?

Dr. Stieg: Yep.

Dr. Basner: That’s one thing with noises, you know, that habituation is not complete. Even people who have been exposed to noise for, for a number of years, they’re still reacting to the noise and the noise is still disturbing sleep about at a much lower level compared to somebody who’s just moving into the area and newly exposed to the noise.

Dr. Stieg: Mathias, this really is an epidemic problem in America. And certainly with the aging population, it’s going to become a bigger problem and as people become more isolated from one another, we will begin to see other health problems as well. So thank you so much for enlightening us. And I’m going to go out and buy a smartwatch today.

Dr. Basner: Thanks for having me.