Announcer: Welcome to Stuff from the Science Lab from howstuffworks.com.
Allison Loudermilk: Hey, guys, and welcome to the podcast. This is Allison Loudermilk, the science editor at howstuffworks.com.
Robert Lamb: And this is Robert Lamb, science writer at howstuffworks.com. And I have to ask, what's the most annoying sound for you personally?
Allison Loudermilk: The most annoying sound has got to be my dad snoring. I'm sorry, Dad, but it's true. Anyone snoring, really - but I have this vision of going cross-country on a college tour. And my dad and I shared a hotel room and he snored so loudly. And I remember contemplating sleeping in the bathtub, although I never did. And this was before I got familiar with all the different kinds of earplugs out there. What about you?
Robert Lamb: Well, I've had to be around some snoring people before. We went on some sort of youth trip in high school.
Allison Loudermilk: I'm tempted to ask if you're a snorer, but I will not.
Robert Lamb: I do not think I'm a snorer. If I am a snorer, then people who have slept near me have been amazingly polite my entire life.
Allison Loudermilk: Very kind.
Robert Lamb: It would be a shocking revelation. But the noise that annoys me the most is anything in a movie theater that is not the movie. And I'm actually - this is why I never go to the theater. I'm super picky about this. If I have to hear somebody eat popcorn, I get irritated. Even though people who don't even like popcorn go to the movie theater and they feel like they have to eat popcorn. And I'm trying to listen to some heartfelt scene, or it's something really violent and disturbing - and then to hear somebody chomping down. Or it's nachos. And anything else, too - cell phones, chitter chatter - it gets to me.
Allison Loudermilk: I have to confess, when you first asked me when we were talking about this podcast what the most annoying sound in the world was, I was thinking about the movie Dumb and Dumber. So moving on to noise pollution!
Robert Lamb: Yeah, basically we're talking about noise pollution. Now a lot of noise pollution, at least as far as it concerns humans does come down to sounds that are annoying and disruptive.
Allison Loudermilk: And sounds that are loud.
Robert Lamb: I keep thinking back to this awesome segment on a British comedy show called Look Around You. It's a parody of science shows for young people. It's great. If you get a chance, do a Google or YouTube search on the name Leonard Hatred and it'll take you right to this. This fictional character comes on the show and he's talking about how his parents snored when he was a child and they lived by Heathrow Airport. But then they moved because it was too noisy, but they moved into a house that was next to Gatwick Airport. Then he left. He got married and moved to the countryside, then somebody built an abattoir directly across the street from the house.
So he had to listen to the sounds of cattle being slaughtered all the time. And to top that off, his wife and the sister-in-law that lived there with him suffered from a condition that caused them to scream uncontrollably. So he developed this spray called Psilence. And he would spray it onto his ears and it he admitted that it contained "liquid skin." So he's spray it on and it would cause skin to temporarily grow over his ears so he couldn't hear anything.
Allison Loudermilk: So he just had a solid ear structure.
Robert Lamb: Yeah, just a solid fleshy knob for an ear.
Allison Loudermilk: Yeah, no nifty ear canal - all of that stuff, gone.
Robert Lamb: It's pretty gross.
Allison Loudermilk: Pretty gross, Mr. Hatred.
Robert Lamb: So let's talk about noises and how these different levels of noise affect human health.
Allison Loudermilk: Let's take it down a notch, shall we?
Robert Lamb: Yeah, let's break it down to decibels.
Allison Loudermilk: All right. So near total silence, you're going to have decibels going on.
Robert Lamb: Yeah, here's an example. [Pause] Got it? All right. Next.
Allison Loudermilk: Well, we're assuming that listeners are listening to us in total silence.
Robert Lamb: Well, I assume that. I demand it, actually. If you don't have time to listen to us in a closed environment, then come on. What are you, in your car? Pull over. What are you doing?
Allison Loudermilk: Now we have a whisper. So give us a whisper. I don't think I've ever heard you whisper. Give us a whisper.
Robert Lamb: Hey, guys. Thanks for listening to the podcast.
Allison Loudermilk: Right. So running roughly around 15 decibels! And then we get into normal conversation.
Robert Lamb: Right, like we're having now. And that's -
Allison Loudermilk: Although sometimes we get excited, so it escalates a little bit.
Robert Lamb: Yeah, but just normal conversation, that'll be 60 decibels.
Allison Loudermilk: Okay, vacuum cleaner - what do you think your robotic vacuum cleaner does?
Robert Lamb: Probably around 70 decibels.
Allison Loudermilk: Is it loud? I would think it might be -
Robert Lamb: Maybe it's a little quieter, but the Rumba tends - you can't sleep with it running. It still sounds like a vacuum cleaner.
Allison Loudermilk: Doubtless, there is someone who does sleep with their vacuum cleaner running - maybe as a timesaver. Well, I guess a Rumba, by nature, is a timesaver.
Robert Lamb: Yeah, you don't have to supervise it. And actually, I'd be a little hesitant to let that thing have free run of the house while I was asleep.
Allison Loudermilk: Afraid of losing an appendage?
Robert Lamb: You never know.
Allison Loudermilk: So your average passenger car doing 65 miles per hour for around 25 feet, that's going to be about 77 decibels.
Robert Lamb: Yeah, if somebody honks the horn, you've got 110 decibels.
Allison Loudermilk: All right, so we're ratcheting up the levels. Now we're heading to a rock concert. What do we have now?
Robert Lamb: 120 decibels. Fire off a gun or light a firecracker - 140 decibels. And if you're within close proximity to a jet taking off you're looking at 150 decibels and a ruptured eardrum most likely.
Allison Loudermilk: Great. That's great.
Robert Lamb: So it basically breaks down to, any sound above 85 decibels can cause hearing loss. And the loss is related to both the power of the sound, the length of exposure, and the proximity to it. So it's a difference between having your head next to a jackhammer, hearing a jackhammer across the street, and having to work in a sandwich shop next to the jackhammer all day long.
Allison Loudermilk: Right. Which is why agencies like OSHA regulate noise exposure on the job? So as an example of this, if you have to raise your voice to be heard, you're probably dealing with noise of about 85 decibels.
Robert Lamb: Yeah. So, think back to the last time you were out at a club or at a rock concert, if you were having to shout to be heard then you were in a pretty noisy environment.
Allison Loudermilk: And when you're talking about eight hours of about 90 decibels, then you're talking about ear damage.
Robert Lamb: And at 140 decibels, like the gunshot or firecracker -
Allison Loudermilk: Yeah, you're not waiting eight hours at that point. At that point, it's immediate.
Robert Lamb: Immediate damage and actual pain.
Allison Loudermilk: Oh, really?
Robert Lamb: Did you ever see Copland?
Allison Loudermilk: I don't think I did see Copland.
Robert Lamb: It was the movie where Sylvester Stallone played a cop and put on weight for it. He has hearing damage in one ear, and the villain of the piece - I think it's Harvey Keitel - they rough him up at one point and fire a gun next to his other ear because they're bad guys. So that would be a situation where you would have immediate hearing damage and pain in the ear.
Allison Loudermilk: And even when a noise isn't actively deafening you, it can have health effects - hearing loss, disturb sleep, cardiovascular problems, and even your social behavior.
Robert Lamb: Yeah, I actually ran across some cool studies.
Allison Loudermilk: Especially with the advent of iPods, I would think there's a whole lot of money pouring into research on hearing loss and tinnitus with the ubiquitousness of iPods - which is what you guys are probably listening to us on now. So I'm not knocking on iPods, but a lot of us listen to them at levels that are way too loud.
Robert Lamb: Yeah, and part of it, too is because you're like on the train, so there's a noisy train sound. And then there's also some annoying chatter - or whatever else is going on the train - you want to block that out. So you crank up the headphones a little and it all adds up.
Allison Loudermilk: So talk to me about some of these studies.
Robert Lamb: So the Department of Psychiatry and the University of London conducted an in-depth study in 2003. And they came to some interesting conclusions. They said the risk of developing mental or physical illness due to environmental noise is actually pretty small. You're probably not going to be driven completely crazy. And this is ruling out actual damage to your hearing. But they said part of the problem is that interaction between people, noise, and ill health is a complex relationship. Humans are not usually passive recipients of noise exposure, and they develop these coping strategies to reduce the impact, or they move away from the noise.
Allison Loudermilk: Have you heard about situations in which prisoners are subject to constant noise in a modification of torture, I suppose. I mean, that sounds horrible.
Robert Lamb: It's like when they were trying to get Noriega out of his compound in Pana
Allison Loudermilk: I don't remember this.
Robert Lamb: And they were pumping rock music. Actually, there was a recent document that came out talking about different music that was used as an instrument of interrogation or torture on Guantanamo Bay inmates.
Allison Loudermilk: Yeah, I think that's where I heard this.
Robert Lamb: I think some of Trent Reznor's music came up for Nine Inch Nails, and he was legitimately offended. You create this art and then somebody's going to use your art to inflict psychological pain on somebody. So one of the factors here is that people can cope with different levels of noise pollution, and they can move away from it.
Allison Loudermilk: Well, assuming they can move away from it. So there's an element of choice.
Robert Lamb: But then a lot of it comes down to how it affects your quality of life. There's the hearing loss, but it also disturbs your sleep. If you have to listen to the jackhammer all night, or if you live next to an airport or something - not getting enough sleep can severely harm your ability to function during the day.
Allison Loudermilk: No doubt.
Robert Lamb: In children, chronic aircraft noise exposure has been found to impair reading comprehension and long-term memory. And it may be associated with raised blood pressure - further research pending on that. And then there's a 2005 study from a team of Spanish researchers, and they found that in urban areas, households are willing to pay approximately four Euros per decibel per year for noise reduction. So that's interesting to think of in terms of your ability to move away from it. It becomes a privilege - at least in some places. It depends on how your urban environment happens to work.
And in 2007, the World Health Organization Noise and Environmental Burden on Disease Working Group published findings on health related effects of noise for Europeans. And they concluded that about two percent of Europeans suffer severely disturbed sleep and 15 percent suffer severe annoyance due to environmental noise. And that's defined as community noise omitted from road traffic, trains, and aircraft flying over.
Allison Loudermilk: And so when I was younger, I lived in the big city for almost a decade. I went to college and then lived there for a couple of years after. And it's weird to me because I am sensitive to noise. If you were to come visit us in our Atlanta office, even the editorial department, you can hear a pin drop. A lot of the other departments around howstuffworks.com are a little noisier and a little rambunctious, especially when the developer guys are around and they're doing all sorts of crazy stuff. But the editorial department tends to be a little quieter. But the point of the story was it was just surprising to me.
I would've thought that I would've gotten used to noise exposure, living in an urban environment for a period of a couple of years.
Robert Lamb: When the in-laws come to visit, they always comment on the sound of airplanes flying overhead.
Allison Loudermilk: Right. From the airport in back of your house?
Robert Lamb: Well, no, but there's an airport in the area. We have a huge airport in the Atlanta area, but it's not in the backyard. And I tend not to even think about it. But they come and stay and they're like, "Oh, I don't see how you deal with this." And I have to stop and think, "Oh, yeah. I guess there are planes flying overhead constantly."
Allison Loudermilk: Yeah, same here. We have a train that runs through the middle of town and I really don't notice it. And again, with the parents staying, they're like, "Oh, that train was so loud last night."
Robert Lamb: So again, it comes down to growing accustomed to certain levels or noise or figure out how to cope with it.
Allison Loudermilk: Right. And we're not the only life forms that are affected by noise pollution. Of course, other animals are, too.
Robert Lamb: We've been a little selfish so far in this podcast.
Allison Loudermilk: Yeah, a little egocentric. So let's talk about some animals and ways in which they deal with noise pollution. A lot of us have heard about stuff affecting whales and all sorts of marine creatures, although we don't really know a lot about how noise pollution affects fish. That's one interesting fact we found when we were researching this. But for whales, noise pollution can mean a couple of things as a way to cope - they can call louder to be heard above the ruckus.
Robert Lamb: Again, it's like you're at the rock concert and having to speak louder. They're having to do the same thing in the ocean to communicate or use their echolocation.
Allison Loudermilk: Actually, the blogger over at Discovery News, Jennifer Viegas, covered this in a July 2010 article. And the title was Whales Scream Over Noise Pollution. And that's a disconcerting idea, that we're causing whales to scream.
Robert Lamb: Yeah, that's a great headline. Because screaming whales, that's immediate outrage.
Allison Loudermilk: Yeah, pretty much. And so there's also research that North Atlantic right whales and other whale species are in fact engaging in this behavior to be heard above stuff like commercial ships and other manmade noises in the ocean. A lot of that is sonar or off shore drilling, stuff like that.
Robert Lamb: Yeah, we went into some of this in our podcast about beached whales.
Allison Loudermilk: Oh, that's right. That was a long time ago.
Robert Lamb: Because that's one of the things they've been looking into, like navy vessels interfering with their echolocation and driving them off course.
Allison Loudermilk: And it can be troublesome when the manmade noises are occurring in the same frequencies as the whale's calls. That's going to start affecting stuff, whether it's migration of mating, or generally whales communicating with each other.
Robert Lamb: Yeah, if you get on an airplane, they ask you to turn off your cell phone during key parts of the flight so you don't interfere with anything. It's like that, we're just not very considerate. When it comes to us going out in the ocean, we're the jerk that won't turn his cell phone off.
Allison Loudermilk: It's important to note that noise pollution can also come from natural sources, like earthquakes for example. So what's the deal with whales? Is it easier to constantly shout or just go quiet? Well, we get tired of shouting and whales, I imagine, do too. So shouting can be this huge energy expenditure. So sometimes they will wind up going quiet. And what does that mean? It means we're never going to know what's being said in whale calls or songs, such as that of the male humpbacks. They engage in these beautiful whale songs.
Robert Lamb: It's like the dude with slight hearing loss that goes to a noisy restaurant. He can't really hear anybody, so he just doesn't say anything. So you miss out on the whole conversation with that guy.
Allison Loudermilk: And it's not just on the oceans or the marine environment, it's also on land. Like we were talking about before, you have aircraft and traffic noises doing a lot to contribute to a really noisy environment. And you think, "Well, I'll just take it over Yellowstone or some national park and I won't be affected by noise pollution." But again, just as we were talking about with light pollution, you can't escape the noise there.
Robert Lamb: I was actually in Yosemite recently on vacation.
Allison Loudermilk: How excellent for you.
Robert Lamb: And it's interesting to go there. You hear these stories about how the park used to do. They used to do this thing called the fire fall where they had burning embers go over the side of this cliff. Or the park ranger would feed trash leftovers from the restaurants directly to the bears -
Allison Loudermilk: Oh, that sound like a great idea.
Robert Lamb: - so everybody could watch. And we're laughing and outraged now, but they like to point out that this was considered okay then. 30 years ago this was perfectly fine. 30 years from now, who knows? People look back and say
, "I can't believe they let people drive cars into these places, or they let them have a golf course." So you go into even these pristine environments in places where nature is the center attraction, but there's still the sound of construction or the sound of a truck bringing groceries up the mountain.
Allison Loudermilk: So let's talk about a couple of the animals that are being affected by noise pollution, such as the Great Tit Parus Major, they're singing at higher frequencies.
Robert Lamb: And then you also have female gray tree frogs, and those are exposed to the sound of passing traffic, so it takes them longer to locate and find males.
Allison Loudermilk: European tree frogs, on the other hand, are just calling less overall.
Robert Lamb: Then also the sound of overhead aircraft can disturb the behavior of harlequin ducks, as well as goats.
Allison Loudermilk: Remind me again what a harlequin duck is?
Robert Lamb: It's a duck that's frequently used for entertainment purposes in the courts of Europe. It's just a variety of duck.
Allison Loudermilk: And then you have stuff, of course, the greater sage grouse and mule deer that are steering clear of noise producing oil and gas developments. And it can also affect the ability of a lot of animals, like owls and bats, to find and hunt their prey.
Robert Lamb: Yeah, these guys depend on sound to find their food. So the laboratory studies have shown that if they encounter areas where there's a lot of noise, they just start avoiding those areas. We're talking about reduced habitat, which can ultimately put a species at a higher risk for extinction. The way I like to think about it is, if you have a wild animal in its natural habitat - if you were to build a mini mall where its habitat is, then it cannot live there anymore. Likewise, if -
Allison Loudermilk: What is a mini mall?
Robert Lamb: A mini mall - like a strip mall.
Allison Loudermilk: Oh, okay.
Robert Lamb: But even if it was just an open space and you had a tremendous amount of noise, that space is occupied by a noise that it cannot cope with. So that cuts off that whole area. It's as if you built a mini mall there.
Allison Loudermilk: And a lot of land in the continental U.S. is in fact really close to roads, which are a great source of noise. So there was a stat that we found, 83 percent of land is within just one kilometer of a road.
Robert Lamb: Yeah, at that distance the sound of an average car is around 20 decibels. And at the same distance, trucks and motorcycles - 40 decibels.
Allison Loudermilk: That's a lot of noise. So what can we do?
Robert Lamb: Well, a lot of it breaks down to make less noise.
Allison Loudermilk: Be quiet, people.
Robert Lamb: Yeah, it's simple. The thing is, our lives are pretty noisy. So you can't just say, "Stop driving vehicles or stop using roads." So the better solution ends up being things like, have quieter road surfaces. Put up noise barriers, like the walls you see when the interstate goes through a major city.
Allison Loudermilk: Here's a good one, appropriate signage in protected areas. But this also reminds me of the signs you'll sometimes encounter in different neighborhoods about no honking your horn, or the laws they have about cruising the neighborhood, you can only go by it once in some set amount of time. And I assume there are also laws about how loud your radio can be and stuff like that. Or even, in the subway you can't bring a boom box, although people do. And it's crazy how loud people can make their cell phones on subways.
Robert Lamb: That's the thing that gets me. If a dude were to bring a boom box on and listen to his music, at least he's -
Allison Loudermilk: Do they still make boom boxes?
Robert Lamb: Yeah, totally. I would respect that a lot more than the guy who brings on a cell phone and is going to play some track off his cell phone aloud. It's just this tinny noise coming out. You're not even able to -
Allison Loudermilk: You don't even hear anything on the subway anyway because you're Mr. Anonymous with your sunglasses and your music or your podcast all turned up loud.
Robert Lamb: But still, sometimes there'll be that one dude. And you're like, "What's going through your mind? Get some headphones for that thing. It's got a headphone jack on it. They're not that expensive."
Allison Loudermilk: So now we know one of Robert's pet peeves. So what else can we do? We can restrict motorized travel, like you guys are going to think, in protected areas in addition to appropriate signage.
Robert Lamb: And that would be like maybe you don't let people drive along all the roads that go through a national park. And certainly, I think they've cut down on travel through a lot of the road. I think there was a time when there was roads every, let's just drive.
Allison Loudermilk: Yeah, certainly. Like in the 1950's in the United States, they were just building out the highway system everywhere.
Robert Lamb: So yeah, simplify that.
Allison Loudermilk: But I feel like some of the things we've mentioned so far are really addressing the symptoms and not the cause of the problem, not the illness itself. So this next one is pretty interesting in that it tries to tackle aircraft. And it's called The Silent Aircraft Initiative. So this is a Cambridge/MIT venture that was discussed a couple of years back.
Robert Lamb: And they have this awesome idea for a silent aircraft. They model that they're looking at particularly is the SAX-40 - that's the silent aircraft experimental. There have been other designs on it as well. The thing is, when people design an airplane, they tend not to think about the noise. Even if you're dealing with a stealth airplane or something, it's not the noise you're thinking of. It's going to be as loud as it's going to be, deal with it. That's the approach. So these guys have redesigned the airplane thinking, "What can we do from a design standpoint that cuts down on the noise?"
Allison Loudermilk: And I think we should take a second to note that it's not going to be silent.
Robert Lamb: Yes. Whenever they refer to silent, they put it in quotations.
Allison Loudermilk: So we're talking about an aircraft whose noise would probably be, hopefully, imperceptible if you're going outside the perimeter of your regular urban airport.
Robert Lamb: And I think the timeframe they were looking at was maybe 2030, they'd have something.
Allison Loudermilk: So you guys are not going to be flying on this anytime soon.
Robert Lamb: But the mere fact that people are working on it is great.
Allison Loudermilk: I am curious about some of the engineering stuff they have going on inherent to lower noise pollution. Can we just check out some of these for a sec?
Robert Lamb: As a side, they're also looking at improved fuel efficiency.
Allison Loudermilk: Great.
Robert Lamb: But they're looking at installing engines imbedded within the fuselage with intakes above the wings to shield most of the engine noise from listeners on the ground.
Allison Loudermilk: So I guess they're redirecting the noise, it sounds like.
Robert Lamb: And they have this novel ultra high bypass engine with a "variable area exit nozzle." This just means the engine can operate for low noise with low speed exhaust jets at take off and during climb. And then it can be optimized for minimal fuel burn during cruise. So it's just gearing it down a little in terms of how much noise it's putting out and how much fuel it's consuming to fly.
Allison Loudermilk: Yeah, they've also rejiggered the engine exhaust ducts to that they can absorb the sound, which I thought was cool as well. But again, this is not going to be coming to an airport near you for a while.
Robert Lamb: Yeah. But it's just such a great idea. Maybe the ultimate take-home from this is what can be applied to every other aspect of our lives, to redesign and rethink - let's redesign the airplane so it makes less noise. Can we redesign our house or our lives so it has less impact on the environment and the lives around us?
Allison Loudermilk: But I think culturally speaking, noise has such an important part in our lives. We were talking about driving cars before. If you happen to drive a Prius and they've come up with a noisemaker for your Prius if you're not used to how silent your Prius drives. So it's interesting to me that noise provides cues to us that we're not used to living without.
Robert Lamb: Not to just continually harp on public transportation, but I think of -
Allison Loudermilk: There's nothing wrong with going on public transportation, mister.
Robert Lamb: But when you go to the train stops here in town, the MARTA stops, there's a lot of noise there obviously because you have a train moving through it. But then they also pipe in this horrible muzak noise that nobody's listening to. I can't imagine anybody -
Allison Loudermilk: I do. At the holidays, I totally listen to it.
Robert Lamb: But when you take MARTA do you?
Allison Loudermilk: Yes, I do.
Robert Lamb: Okay.
Allison Loudermilk: Especially in the morning when I'm too brain dead to do anything else and somebody's cheerily singing.
Robert Lamb: I'm not talking about singing, I'm talking about the music they're piping in.
Allison Loudermilk: Well, I can't think if it's muzak or if it actually has voices. But I listen to the holiday music.
Robert Lamb: Well, maybe some people like it. I'm just saying, strictly speaking, is it necessary? Is it something we could scale back on and make the world a quieter place?
Allison Loudermilk: Yeah. If you guys have ideas on how to make a quieter planet, please send them to us. We're at firstname.lastname@example.org. But before we wrap it up, let's hear from a listener.
Robert Lamb: Yeah, I've got a cool email here from Mark. He writes, "Just listened to your August 31st podcast in which you chatted about evolution, and slugs at the end of the show. It made me think of the Ricky Gervais podcast audio book as Karl Pilkington has some interesting theories about evolution and absolutely hates slugs." And then he points out that there's a free promo that came out on YouTube a few years back. But I actually listened to it and a lot of it is this guy just sort of not understanding evolution and Ricky Gervais trying to explain evolution, and then the guy talking about how he hates slugs, which I hate as well.
But Gervais made an interesting point about slugs that made me have to s
top and rethink them. I tend to think that they're worthless and disgusting.
Allison Loudermilk: But we already talked about why they're worthless.
Robert Lamb: Well, he pointed out that they're perfect. They've been around for so long they're filling this particular role in life itself. That's a perfect design. You may be grossed out at it, but that slug is perfect. Same thing when you think snakes or spiders are gross. Well, you're looking at a perfect design.
Allison Loudermilk: Sure. Basis of ecology. Gotta love 'em.
Robert Lamb: Yeah, so thanks, Mark. I appreciated checking out that link.
Allison Loudermilk: If you guys want to send us your thoughts on slugs or the noisy world we live in, again we're at email@example.com. And over on Facebook and Twitter we're kind of quiet, but very active.
Robert Lamb: So check us out on Facebook where we're Stuff from the Science Lab. Or you can also go to Twitter where we're @LabStuff. And we'll try and keep you updated on cool stuff that we're finding out about and stuff that we're podcasting about.
Allison Loudermilk: Yes, that's all we've got. Thanks for listening, guys.
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