Speaker 1: Brought to you by the reinvented two thousand twelve camera.
Speaker 1: It's ready. Are you get in touch with technology with
Speaker 1: tech Stuff from how stuff works dot com. Hello again, everyone,
Speaker 1: and welcome to tech Stuff. My name is Chris Poette
Speaker 1: and I am an editor here at how stuff works
Speaker 1: dot com and sending a cross from me as usual
Speaker 1: as senior writer Jonathan Strickland. What so early in the podcast? Okay, yeah,
Speaker 1: I had I had predetermined that I wasn't going to
Speaker 1: make our classic joke. Right. Well, let's let's clue in
Speaker 1: our our listeners to what we're talking about, and we'll
Speaker 1: do that through a little listener mail. This listener mail
Speaker 1: comes from Christopher, and Christopher says, hey, guys, I was
Speaker 1: mowing the lawn the other day when I thought I
Speaker 1: would break the monotony and listen to my iPod. Then
Speaker 1: I thought how I would need to crank up the
Speaker 1: volume super high in order to hear anything over the
Speaker 1: sound of lawnmower. I decided that this probably wasn't the
Speaker 1: best idea and went on mowing the lawn in complete boredom.
Speaker 1: That got me wondering how do earbuds affect a person's hearing?
Speaker 1: I know it can't be healthy to listen through earbuds
Speaker 1: at a volume level where someone across the room can
Speaker 1: tell which A C D C song you're listening to,
Speaker 1: But I'm sure earbuds will still have a negative impact
Speaker 1: at lower levels. How do I know what a safe
Speaker 1: listening level is? What, if anything, our company is doing
Speaker 1: about this? Thanks a much, Christopher Chris So obviously my
Speaker 1: joke at the beginning was a joke in poor taste
Speaker 1: about hearing loss which I actually have. What Yeah, nice,
Speaker 1: I was putting it in context there, so and and
Speaker 1: polite of course is a percussionist. Now, just a quick question,
Speaker 1: do you do you actually have hearing loss? Not that
Speaker 1: I'm aware of, But then again I've been I've been
Speaker 1: practicing and actually performing with ear plugs in for years now,
Speaker 1: very very wise. And as a matter of fact, to
Speaker 1: to Christopher's point, I mow the lawn of ear plugs
Speaker 1: because I don't even the sound of the lawnmower by
Speaker 1: itself without adding music or something else on top of it.
Speaker 1: You know, that's that's pretty loud. So that is Mr
Speaker 1: Pillette's version of the rock and roll lifestyle. Yeah, if
Speaker 1: it's more like the soft rock lifestyle. Nice nice, Well,
Speaker 1: Jonathan Colton has a song for you. Um, So I
Speaker 1: was going to talk a little bit before we really
Speaker 1: get into the whole earbuds thing. Yeah, I'm gonna talk
Speaker 1: a little bit about how hearing works. Oh, that's a
Speaker 1: good idea, so that we can kind of get a
Speaker 1: handle on why loud sound can be a problem. So
Speaker 1: here's the general process that happens when we hear a sound. So,
Speaker 1: of course sound travels and waves right there, sounded as
Speaker 1: created as a longitudinal wave and as it crashes into
Speaker 1: the medium, they create a uh different kind of wave, right,
Speaker 1: you know, longitudinal waves right right, So you've got these
Speaker 1: these waves. Essentially you have air molecules banging into each other, right,
Speaker 1: and then those travel they get captured by your ear.
Speaker 1: Your ear is shaped in the way that is, it's
Speaker 1: kind of like a funnel sort of funnels sound into
Speaker 1: the canal of your ear um. The sound travels down
Speaker 1: and it it makes contact with your your ear drum
Speaker 1: right right, So this causes the ear jump to vibrate. Now,
Speaker 1: the ear drum is connected to a little bone that
Speaker 1: we call the hammer um. It's one of three tiny
Speaker 1: bones that are in your middle ear. There's the hammer,
Speaker 1: the anvil, and the stirrup, all right, right, So the
Speaker 1: hammer is connected to the anvile anivivals connect to the stirrup,
Speaker 1: and the stirrup is connected to the cochlea, which is
Speaker 1: the snail shaped element in your inner ear, all right.
Speaker 1: So the ear drum vibrates. This in turn causes those
Speaker 1: bones to vibrate and it kind of presses against the
Speaker 1: little Think of it like a little window in the cochlea. Now,
Speaker 1: the cochlea is filled with fluid and actually has two
Speaker 1: chambers separated by a membrane, and the membrane has a
Speaker 1: tiny little hole in it which allows the fluid to
Speaker 1: move back and forth between the two chambers. And inside
Speaker 1: the cochlea are thousands and thousands of little cells with
Speaker 1: tiny little hairs in them. Now, as the fluid vibrate
Speaker 1: or moves through the cochlea, that causes those hairs to vibrate.
Speaker 1: These these vibrations get converted into electrical impulses which go
Speaker 1: to your brain, and that's how you perceive sound. Your
Speaker 1: brain receives that that those electrical impulses and says, ah,
Speaker 1: that's a dog barking. All right. So that's that's it's
Speaker 1: kind of a it's actually a really fascinating process. I mean,
Speaker 1: anything that involves that kind of level of biology to
Speaker 1: me is fascinating. Um. And if you remember when we
Speaker 1: did our Cyborgs podcast, we talked about cochlear implants and
Speaker 1: cochlear implants bypassed the ear drum, bypass all of that.
Speaker 1: They they have electrodes that actually go against the cochlea
Speaker 1: so that it it simulates those electrical impulses that would
Speaker 1: otherwise have been created by those little tiny hairs. Here's
Speaker 1: the thing. Those cells inside the cochlea are both delicate
Speaker 1: and they do not heal if you damage them. If
Speaker 1: you damage those cells, if they they they stop working,
Speaker 1: you start to lose hearing and there's no way to
Speaker 1: get it back. Right now. That's a bummer. Yeah, So
Speaker 1: I mean to put it mildly, I was trying to
Speaker 1: be sort of something facetious, but yeah, I mean, that's
Speaker 1: that's serious. It's something that you don't want to mess with,
Speaker 1: right And I mean there's like twenty four thousand of
Speaker 1: these cells in your in each cochlea, and like I said,
Speaker 1: you know they are easily damaged. And once they're damaged,
Speaker 1: that's it. And loud noises can do that. It's you know,
Speaker 1: you think about it. The vibrations of your urge from
Speaker 1: are fairly small, but they're magnified by those three little
Speaker 1: bones because they're they're pressing against a very very tiny
Speaker 1: spot on the cochlea. So everything that happens to the
Speaker 1: ear drum is magnified once you get down to the
Speaker 1: cochlea level. So if you're playing really or listening to
Speaker 1: really loud sounds, or you're subjected to really loud sounds, um,
Speaker 1: you're really given it a workout. So that's what can
Speaker 1: actually cause damage to those cells. And we're not talking
Speaker 1: about just using earbuds. This can be any kind of
Speaker 1: loud sound, right, that could damage You're here, you don't
Speaker 1: even have to have headphones on, I mean if you were.
Speaker 1: That's why you see people who work at airports having
Speaker 1: ear protection on at all times, because if you know
Speaker 1: those jets make up, they make really loud noises. And
Speaker 1: of course we we measure these noises and decibels and
Speaker 1: uh and in general, once you get over a hundred decibels,
Speaker 1: you're starting to get into the dangerous area. And it's
Speaker 1: it's a matter of not just the intensity, but the
Speaker 1: time that you spend listening to that sound. Right, So,
Speaker 1: if you hear like a really loud noise, it's not
Speaker 1: like you're going to necessarily suffer damage just from one
Speaker 1: I slated incident. But if you're hearing a series of
Speaker 1: loud noises, for example, an A C D C concert
Speaker 1: for a nice long time, that's more likely to over
Speaker 1: the course of the evening cause hearing loss. And it
Speaker 1: may not be perceptible immediately thereafter. It just might mean
Speaker 1: that you will experience more dramatic hearing loss faster than
Speaker 1: you would otherwise. Yes, so let's get down to earbuds
Speaker 1: now that we've covered those bases well at the answer
Speaker 1: to the question that that Christopher post this is actually
Speaker 1: fairly simple, depending on whom you ask um for me,
Speaker 1: I would have I would have asked Dean Garstecki, Northwestern University. Guy. Yes,
Speaker 1: the professor in the chair in the rox Lyn and
Speaker 1: Richard Pepper Department of Communication Sciences and Disorders. Audiologist is
Speaker 1: what is one of his titles, that's the shorter one. Yes, anyway,
Speaker 1: he deals with here and hearing loss and knows a
Speaker 1: lot of people who do. Um and uh, which will
Speaker 1: be important later. Um. And the thing is, he says,
Speaker 1: um frankly, he has what he calls a sixty sixty rule.
Speaker 1: Have you I think you've seen this. I got mine
Speaker 1: my information from a Science Daily article. Um. But yeah,
Speaker 1: apparently he believes that you should listen to music on
Speaker 1: a set of earbuds no more than sixty minutes a
Speaker 1: day in twenty four hour periods, at no more than so, uh,
Speaker 1: that's pretty simple. Don't listen to your earbuds for more
Speaker 1: than an hour a day at just a little bit
Speaker 1: more than medium volume, right and uh. And he bases
Speaker 1: this mainly as far as I can tell off of
Speaker 1: a typical iPod player. And now the article that you
Speaker 1: are referring to, I read the same one exactly. I
Speaker 1: think it was written in around two thousand five. Yes,
Speaker 1: it was the iPod that was built in two thousand
Speaker 1: five that they were talking about. Had a maximum volume
Speaker 1: level of around a hundred thirty decibels, which is above
Speaker 1: the threshold for what could cause hearing loss if you
Speaker 1: listen to it for for any extended amount of time.
Speaker 1: So six of that would be presumably safer as long
Speaker 1: as you listen to it for an hour or less. Um.
Speaker 1: Here's here's another thing about earbuds. It's interesting. Earbuds can
Speaker 1: actually boost up the the decibel level. Um, Like, if
Speaker 1: you were to measure the decible level by just say,
Speaker 1: hooking up a regular pair of headphones and measuring it
Speaker 1: that way, a pair of headphones that would actually go
Speaker 1: over over your ears over the ear headphones or even
Speaker 1: just the padded kind not necessarily over the ear, but
Speaker 1: you know they don't go into the ears. Yes, on
Speaker 1: your airphones headphones rather, um, those might come in at
Speaker 1: let's say that you measure it and it comes in
Speaker 1: about say eighty decibels, all right, earbuds can boost that
Speaker 1: up up to uh up to nine decibels more than
Speaker 1: the equivalent headphones. And part of that is because it's
Speaker 1: closer to your your actual ear drum, so the sound
Speaker 1: waves are traveling a shorter distance and they aren't dispersing
Speaker 1: as much. They're there the intensity is higher. So the
Speaker 1: eighty decible sound you would get out of a normal
Speaker 1: pair of headphones is gonna jump up to eighty nine
Speaker 1: decibles in earbuds. Now, if you're listening at one of
Speaker 1: the higher levels, then you're you know, each you have
Speaker 1: to remember that as you get closer to that threshold,
Speaker 1: each time, each increment you go over the threshold is
Speaker 1: it's not it's not a linear um uh progression of
Speaker 1: how much more dangerous it is to your hearing. It's
Speaker 1: it's greater than linear. It's not quite you know, lagarithmic,
Speaker 1: but it's somewhere in between. You just wanted to say logarithmic.
Speaker 1: I bet often at any rate. So, yeah, so he's
Speaker 1: got the sixty sixty rule. But you also have to remember,
Speaker 1: if you're using earbuds, you need to make that um
Speaker 1: take that into effect. And of course today you can
Speaker 1: find MP three players that have kind of self imposed
Speaker 1: limits on how loud they can get. Yes, some of
Speaker 1: which you can work around. Right. Well, now, I was
Speaker 1: going to get to to that in and but the
Speaker 1: friends thing. The reason I brought that up was in
Speaker 1: that article he cited a friend of his who worked
Speaker 1: at Wichita State University. And apparently, what this friend will do,
Speaker 1: another professor will walk across campus and and as this
Speaker 1: friend is doing so, um, we'll find students wearing earbuds
Speaker 1: and we'll ask, we'll stop them and ask them take
Speaker 1: out the earbuds and we'll check to see how loud
Speaker 1: they were playing. And in a lot of cases, the
Speaker 1: students were listening to music at a hundred ten or
Speaker 1: a hundred twenty deils. Yeah and uh and Osha recommends
Speaker 1: that you don't listen to any uh, any sound level
Speaker 1: greater than a hundred and ten decibels for more than
Speaker 1: half half an hour a day. Right, So if you're
Speaker 1: listening to music at a D twenty and chances are
Speaker 1: you're listening to it for more than half an hour.
Speaker 1: Most of us, I think probably listen to you know,
Speaker 1: I'd say half hour is a good minimum amount of time. Well,
Speaker 1: that's the thing is, according again to this article, UM,
Speaker 1: all volume at that level can cause hearing loss after
Speaker 1: only an hour and fifteen minutes, which is a pretty
Speaker 1: short period of time. When you think about it, that
Speaker 1: that probably factors into the UM and UM you know, basically, uh,
Speaker 1: the thing is you you there are factors that you
Speaker 1: can and take into account, like the distance between your
Speaker 1: ear and the source of the sound and the volume
Speaker 1: of course, but one thing that the iPods and other
Speaker 1: music players have today that say the early the Walkman
Speaker 1: and UH sound players of the nine eighties and nine
Speaker 1: ninies don't have is a much longer battery life, and
Speaker 1: that's a problem because, um, they will last for hours
Speaker 1: and hours, especially when they're new, and if you're listening
Speaker 1: to music UH within ear bud in your ear at
Speaker 1: that volume for an extended period of time, you're more
Speaker 1: or less guaranteed to cause hearing loss. If nothing else,
Speaker 1: you have the ear fatigue, which you know, that's when
Speaker 1: you when you take them out and you just feel
Speaker 1: like like things just don't sound right to you anymore.
Speaker 1: Everything's kind of muffled. That's a good indication that you've
Speaker 1: caused some some damage to your hearing. It may not
Speaker 1: be it may not stay that severe for forever. It
Speaker 1: may be that gradually you start to, you know, notice
Speaker 1: that you've got your hearing back. But what it means
Speaker 1: is that those cells, even if they aren't dead, are damaged,
Speaker 1: and that over time they can get more damaged until
Speaker 1: they stop working entirely. So it may not mean that
Speaker 1: you lose a perceptible amount of hearing at that time,
Speaker 1: but it means that over the long run, you're gonna
Speaker 1: lose your hearing. Faster than you would have otherwise. Um.
Speaker 1: And it has been going on since the the ear
Speaker 1: the headphone phenomenon of portable music players, having your your
Speaker 1: music with you anywhere and everywhere. Um. You know, the
Speaker 1: research I I had seen basically said, you know, yes,
Speaker 1: there there have been more people losing their hearing before
Speaker 1: you know, old age, when you might expect people to
Speaker 1: start losing their hearing. Um, since people have been carrying
Speaker 1: around their music with them and using portable music players.
Speaker 1: So yeah, it's it's certainly an issue. The Center for
Speaker 1: Disease Control and Prevention out here in Atlanta actually reported
Speaker 1: that noise induced hearing loss. Uh, they found noise induced
Speaker 1: hearing loss in nearly thirteen percent of Americans between six
Speaker 1: and nineteen. So you think about that. I mean, yeah,
Speaker 1: hearing loss is usually one of those things that comes,
Speaker 1: like you said, along with aging. But between the ages
Speaker 1: of six and nineteen, you know, these are these are
Speaker 1: when you're still growing. Yeah. Um, well maybe not nineteen,
Speaker 1: I mean, but I was growing at nineteen. I was
Speaker 1: just growing out. Uh. Also, I thought i'd ask you
Speaker 1: you're familiar with the term tenitus. Oh yeah, Oh, I
Speaker 1: was thinking of it from that Beatles song you know,
Speaker 1: the girl with Tenitus goes by anyway, So, um, so
Speaker 1: about forty to fifty million Americans experienced some degree of that,
Speaker 1: and uh, hyperacusis or I'm just gonna say hyperacusus because
Speaker 1: I have no idea if that's the correct pronunciation, and
Speaker 1: I don't even want to try a different one. Um.
Speaker 1: But yes, the tenetus or tenitus is that it's kind
Speaker 1: of it's it's a it's a persistent sound that you
Speaker 1: hear that's not generated by any external um source. So
Speaker 1: usually it's like it's normally described as kind of a
Speaker 1: high ringing noise, but it can also be a buzzing
Speaker 1: or a worrying noise UM. And then there's uh, it's
Speaker 1: it's one of those things where it can it can
Speaker 1: actually interfere with your hearing of normal sounds, even though
Speaker 1: there's no perceptible like someone who's staying next to you
Speaker 1: is not going to hear it because it's all in
Speaker 1: your in your here ing. Yeah. As a matter of fact,
Speaker 1: a number of rock stars have come forward um to
Speaker 1: talk to young people about listening to music to live
Speaker 1: because they've said, you know what, listening to the loud
Speaker 1: music like I have been every day, you know, with
Speaker 1: these large amps behind me. Uh, well, damage your hearing
Speaker 1: because it's damaged mine. And you know I'm thinking specifically,
Speaker 1: you know, people like Pete Townsend. Um you know who.
Speaker 1: I think he actually suffered a burst ear drum due
Speaker 1: to a certain Keith Moon and his exploding uh drum kit. Well, yes, however,
Speaker 1: I don't think a small explosives count in the earbud department.
Speaker 1: But yes, those are also bad for your ears. So
Speaker 1: so here's a hint, be careful with earbuds and don't
Speaker 1: play directly in front of Keith Moon. That second one
Speaker 1: actually be pretty easy. One's pretty easy these days. Um,
Speaker 1: thanks a lot, it's that Um okay, So I was
Speaker 1: going to make Keith Moon jokes to a drummer, Yeah,
Speaker 1: no kidding. Uh yeah, he's one of my favorites too.
Speaker 1: Um Joseph birds Song and Bruce Wagoner. Did you run
Speaker 1: across these names? They are? There are two people who
Speaker 1: filed suit against Apple, uh specifically against Apple, saying that
Speaker 1: it's ear drugs. The earbuds were designed to be put
Speaker 1: deep into your ear canal and uh is you know,
Speaker 1: are specifically going to be a problem. Um, you know
Speaker 1: They also argue that there is no visual representation of
Speaker 1: the volume. Of course there is when you're actually speaking
Speaker 1: of somebody who's owned two different generations of iPods. Yes,
Speaker 1: you can see roughly how loud it is as you're
Speaker 1: you know, making a change to the volume or stopping
Speaker 1: or pressing play. But you know, if you're not looking
Speaker 1: at it, and you know, the screen goes blank. No,
Speaker 1: there's no longer a visual representation of volume, nor is
Speaker 1: there sound isolation. And they were asking for for monetary damages,
Speaker 1: not because they had actually lost hearing themselves, but basically, uh,
Speaker 1: you know, to get Apple to improve safety, raise awareness. Um,
Speaker 1: it was better headphones. Right, It was more of a
Speaker 1: a a way to try and convince Apple to change
Speaker 1: there there processes and their systems so that people would
Speaker 1: not suffer hearing damage down the road. Right, right, Well,
Speaker 1: the uh, the Ninth Circuit Court of Appeals, who has
Speaker 1: come up many times in our podcast in California, UM
Speaker 1: had affirmed a two thousand district court ruling about this
Speaker 1: membread an article and Reuter's about this that basically the
Speaker 1: planiffs didn't show that the use of the iPod poses
Speaker 1: an unreasonable risk of noise induced hearing loss. Um and
Speaker 1: uh basically said that they didn't really have because they
Speaker 1: hadn't lost hearing themselves as a result of using the iPod,
Speaker 1: they didn't really have the legal footing to to bring
Speaker 1: a case against Apple. But you know, if they have
Speaker 1: raised awareness, um, you know, they I imagine they would
Speaker 1: say that they have achieved some measure of success. Although
Speaker 1: you know, certainly Apple is not the only one to
Speaker 1: be packaging earbuds with its products. No, No, there are
Speaker 1: plenty of independent earbuds out there that work with just
Speaker 1: about any kind of device that has you know, essentially
Speaker 1: a three and a half millimeter headphone jack Um and Uh,
Speaker 1: I was gonna mention that, you know, it's really it's
Speaker 1: not difficult to create a product that that would uh
Speaker 1: minimize the risk of hearing loss. You just create one
Speaker 1: that has a maximum output beneath the danger zone. Really, Um,
Speaker 1: what should be bad because he wouldn't be able to
Speaker 1: play that? Okay, you beat me to it, um, But
Speaker 1: at any rate, Uh, I'm amazed. You know, we've had
Speaker 1: what like three different three or four different music references,
Speaker 1: oh four because of a c D c um at
Speaker 1: any rate, the h it wouldn't be difficult to do that.
Speaker 1: But I think that the the outcry, weak as it
Speaker 1: may be, from the hearing impaired, um, the outcry from
Speaker 1: the they outcry, the outcry from from people who the
Speaker 1: customers who are purchasing this and saying, you know, no
Speaker 1: matter how loud I turn it up, it's not loud enough. Um.
Speaker 1: I mean I know that. On my iPod. I actually
Speaker 1: bypassed the the safety because there is a safety on
Speaker 1: on Well. The reason I did was not because I
Speaker 1: want to listen to music at a you know, an
Speaker 1: ear drum blasting level. The problem is that sound files
Speaker 1: aren't all recorded at the same volume level. So you
Speaker 1: listen to two different sound files and you you haven't
Speaker 1: even touched the volume, and one might be whisper quiet
Speaker 1: and the other one might be blistering lee loud. Yes,
Speaker 1: the way that people have recorded sound over the past,
Speaker 1: uh you know, a few decades has changed dramatically, especially
Speaker 1: in the last years, and even the way that it's
Speaker 1: converted into the MP three format can that can be
Speaker 1: affected that way too, depending on on your on how
Speaker 1: you're converting things. Oh you know what I wish I
Speaker 1: had done research on and it just occurred to me
Speaker 1: just now. I hate I usually have one of these
Speaker 1: in every podcast, and and normally I keep it to
Speaker 1: myself because I feel uh sad that I didn't think
Speaker 1: of it. But uh, I had read somewhere that um
Speaker 1: that basically because they are trying to improve the hearing
Speaker 1: of certain frequencies in music on recordings they want you
Speaker 1: to hear, UM basically enhance their accenting the parts that
Speaker 1: they want you to hear. Let's say that they're accenting
Speaker 1: the frequencies because they're you're using compression and other techniques
Speaker 1: to make this work, make things seem louder. Um. I
Speaker 1: had read somewhere that, uh that it may cause people
Speaker 1: to lose the ability to hear in other frequencies as
Speaker 1: a result of that, basically, that we won't be able
Speaker 1: to hear anything between twenty and twenty thou hurts. Now.
Speaker 1: I don't know if that's true. I wish I've looked
Speaker 1: that up before this podcast, So don't write in and
Speaker 1: say you didn't say whether it was true. I don't know.
Speaker 1: I'm gonna want to go look it up, and I
Speaker 1: might report back because that would be interesting to to know,
Speaker 1: and and maybe something that they have to do a
Speaker 1: lot of study on before they can really tell for sure.
Speaker 1: But that's sort of like the vestigial toe thing. Like
Speaker 1: I do remember hearing about audio engineers who complained that
Speaker 1: we're losing a lot of the nuance of of music.
Speaker 1: We're losing a lot of the the high highs and
Speaker 1: low lows and and the subtle stuff, and everything is
Speaker 1: just becoming equally loud, which is also why you can
Speaker 1: suffer your fatigue as you listen to music, because it's
Speaker 1: all being blasted at you at the same intensity. There's
Speaker 1: no variation. And then you have, for example, headphones that
Speaker 1: limit you to say twenty to twenty hurts, and then
Speaker 1: you know all the things that theoretically you can't hear,
Speaker 1: but you sort of feel more than here, Um, you don't.
Speaker 1: We really don't get that sort of an experience like
Speaker 1: you would say, if you were at a live concert
Speaker 1: and listening to it in in person. So it's it's
Speaker 1: really kind of fascinating. We think about the science of
Speaker 1: sound and how all that works, and and how our
Speaker 1: electronics are changing that and either enhancing or harding that
Speaker 1: in some degree. Sure, And on a related note, that
Speaker 1: actually brings me to a second round of listener mail.
Speaker 1: This listener mail comes from Daniel, and Daniel says, high, guys,
Speaker 1: So I'm looking at buying the brand redacted headphones and
Speaker 1: was wondering, how are they stereo if they're binaral? What
Speaker 1: does binaral actually mean? Anyway? I thought it meant a
Speaker 1: single channel with two earpieces. Come to think of it,
Speaker 1: how do headphones work in general, especially the noise canceling time?
Speaker 1: Thanks Daniel, Well, we figured since this was kind of
Speaker 1: on the same subject, I would I would tackle this
Speaker 1: really quickly. Binaral is actually a method of recording, it's not.
Speaker 1: It's not a method of playback. Alright, So you're familiar
Speaker 1: with the stereo recording system where you're using at least
Speaker 1: two microphones, right, essentially two microphones space channels two channels
Speaker 1: a channel per microphone. I've got one microphone. Let's say
Speaker 1: let's say you have one setup near like a speaker
Speaker 1: where it's the lead guitarist, and then another one that's
Speaker 1: over by the drums or whatever, and then by recording both,
Speaker 1: you know, the microphones are a good space apart. You
Speaker 1: can get two different channels of sound, mix them together.
Speaker 1: And then you get this, uh, this more complex sound
Speaker 1: than you would if you use just one microphone, right,
Speaker 1: all right. Binaral takes that an extra step. Binaral. What
Speaker 1: they do is they take an analog of a human head,
Speaker 1: and by that I mean like a human head, usually
Speaker 1: a dummy, UM, sometimes a porsche lub who no, no dummy.
Speaker 1: They get a dummies head instead of ears as microphones
Speaker 1: on the directional microphones. UM. Sometimes they go to great
Speaker 1: links to try and uh and and and simulate human ears.
Speaker 1: The idea here being that you set this down in
Speaker 1: a recording area, you play whatever the sound is, and
Speaker 1: it picks up sound as if it were a person
Speaker 1: standing in that exact location. So when you listen to
Speaker 1: the recording, the two tracks are never mixed together into
Speaker 1: a single track. It's you're you're you're getting one track
Speaker 1: in the left ear and one track in the right ear. Um,
Speaker 1: and ideally you would be hearing the sound as if
Speaker 1: you yourself had been standing at the recording session at
Speaker 1: that one time. It's kind of a neat idea that
Speaker 1: works really well for things like classical music. I've heard
Speaker 1: it for audio drama, where you are essentially inserted into
Speaker 1: the audio drama as a mute participant. So you hear
Speaker 1: people walking around you and leaning over and whispering things
Speaker 1: in your ear and that kind of thing. And what
Speaker 1: they're doing is they are physically walking around this dummy
Speaker 1: head and physically whispering things into this microphone, and you're
Speaker 1: hearing it as if you were you were there, I mean,
Speaker 1: the two microphones are spaced apart as if they were
Speaker 1: human ears, so you get the sound at about the
Speaker 1: same speed as you would if you were actually there. Impressive.
Speaker 1: So that's binaral. So really, any pair of headphones can
Speaker 1: do it, and and any pair of stereo headphones can can
Speaker 1: do this sort of thing, and you could even listen
Speaker 1: to it on regular speakers, but you would lose that
Speaker 1: stereo effect unless you had really a good surround separation. Yeah,
Speaker 1: separation is very important with that. And as for noise canceling,
Speaker 1: that's also kind of interesting. The way noise canceling works
Speaker 1: is through a method called destructive interference. Now you talked
Speaker 1: about the longitudinal waves. Yes, sound is created. The information
Speaker 1: I actually got from our article on how noise canceling
Speaker 1: headphones work, right, So what noise canceling headphones do is
Speaker 1: they have a little microphone in them that detects the
Speaker 1: noise and the environment, at least the active ones. The
Speaker 1: active ones, so passive ones, all they do is cover
Speaker 1: up your ears, right, So it's it's essentially the same
Speaker 1: thing as the same method as sticking the fingers into
Speaker 1: the ears. That's essentially what the last I can Active
Speaker 1: ones have a microphone in them that picks up the
Speaker 1: sound in the environment and then it generates a sound
Speaker 1: with the same frequency. But um, but turned a d
Speaker 1: eighty degrees, all right, So they the troughs and valleys,
Speaker 1: peaks and trops, I'm saying the same thing, the troughs
Speaker 1: and valleys, the depths and the valleys and the troughs,
Speaker 1: you know, the peaks and the trops, thank you Pullett,
Speaker 1: Uh match up so that you get one kind of
Speaker 1: solid bar and essentially the two sounds cancel each other
Speaker 1: out right. Um. They basically sort of make a form
Speaker 1: of white noise, if you will. Right. And since they
Speaker 1: are active headphones, they require power. So that's why they
Speaker 1: need to have batteries in them, uh, because otherwise it
Speaker 1: can't generate that signal. Right, And you know, I've listened
Speaker 1: to music on noise canceling headphones, and the nice thing
Speaker 1: about them is that you don't have to turn the
Speaker 1: volume up nearly as much to try and drown out
Speaker 1: all the ambient noise. That's the other problem with earbuds, right,
Speaker 1: is that they aren't good at canceling ambient noise, so
Speaker 1: instead of canceling it, you're just trying to overpower it,
Speaker 1: and that that in turn ends up causing damage to
Speaker 1: your hearing. Yes, and and as Garstecki said, um, noise
Speaker 1: canceling headphones or any kind of headphone that you can
Speaker 1: use to you, uh, you know, prevent to get it
Speaker 1: farther away from your ear, the source of the sound
Speaker 1: farther away from your ear. That's going to help. And
Speaker 1: I assume that that's part of it too, is that
Speaker 1: you're not trying to drown out the outside noise such
Speaker 1: as I want to know, say, a lawnmower, right, so
Speaker 1: I drowned it out with more noise. So well, thanks
Speaker 1: a lot, Christopher and Daniel that those were great questions.
Speaker 1: Had a really good conversation there about the hope you
Speaker 1: heard it. Uh. If any of you have any questions,
Speaker 1: you would like to send us our email address is
Speaker 1: tex Stuff at how stupports dot com. Remember, we have
Speaker 1: a Twitter feed, an official tech stuff Twitter feed. Now
Speaker 1: you can find us on Twitter. Our our handle is
Speaker 1: text stuff h s W all one word, and we
Speaker 1: also have a Facebook fan page, so do a search
Speaker 1: for tech stuff on Facebook. Come on and join the fun, guys.
Speaker 1: We're actually having some good conversations on there, so the
Speaker 1: more the merrier, and Chris and I will talk to
Speaker 1: you again really soon. If you're a tech stuff and
Speaker 1: be sure to check us out on Twitter tech stuff
Speaker 1: hs wsr handle, and you can also find us on
Speaker 1: Facebook at Facebook dot com slash tech stuff h s W.
Speaker 1: For more on this and thousands of other topics, visit
Speaker 1: how stuff works dot com and be sure to check
Speaker 1: out the new tech stuff blog now on the house
Speaker 1: stuff Works homepage, brought to you by the reinvented two
Speaker 1: thousand twelve camera. It's ready, are you