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 everybody,
Speaker 1: and welcome to tech stuff. My name is Chris Poulette,
Speaker 1: and I'm the tech editor here at how stuff works
Speaker 1: dot com. Sitting next to me as usual as senior
Speaker 1: writer Jonathan Strickland. I have the swine flu. Actually, yes,
Speaker 1: yes he does. Yeah, that's I'm I'm beyond the contagious stage.
Speaker 1: But if you guys think I sound a little weird
Speaker 1: or maybe even sounded weird and past episodes, because the
Speaker 1: episodes we recorded last week, I was already coming down
Speaker 1: with it, that's why. And uh, I can report that
Speaker 1: it kind of is awful. It's very much like the flu.
Speaker 1: It is, um, except that apparently I now also have
Speaker 1: the uncontrollable urge to lick pigs. I'll so let's uh
Speaker 1: and then of course lead Yes, I was about to say,
Speaker 1: it leads directly into our topic. UM. Now, I don't
Speaker 1: have a listener mail for this specifically, we did have
Speaker 1: a request for this topic, and it was from a
Speaker 1: listener and it did arrive in mail, but our listener
Speaker 1: Thomas sit in several requests for different text stuff podcast episodes, right, Like,
Speaker 1: he had about five or six different lists topics listed,
Speaker 1: And so we're just gonna tackle one of those today,
Speaker 1: and that one is touch screens. And of course touch
Speaker 1: screens are becoming more and more ubiquitous ever present all
Speaker 1: over the place because things like smartphones. You got a
Speaker 1: lot of cell phones out there that now have touch screens. Um.
Speaker 1: You've got things like the iPod, TOUCHERSK reader right that
Speaker 1: has a touch screen. Um. So yeah, there are a
Speaker 1: lot of them out there. And of course then they're
Speaker 1: always the other ones that have been around for ages
Speaker 1: a t M S. Yeah, good example, vending machines, Um, yeah,
Speaker 1: vending machines. I always think back to, uh, Epcot, the
Speaker 1: old days of Epcot where they would have a computer
Speaker 1: screen and you could walk up to it and touch
Speaker 1: the computer screen and uh and and pull up information
Speaker 1: about the park and about you know, the different aspects
Speaker 1: of the park and make reservations. And this was back
Speaker 1: in the early eighties, you know, when Epcot first opened
Speaker 1: and uh and back then, a touch screen seemed like
Speaker 1: freaking science fiction to me. It was. It was pretty
Speaker 1: amazing because you didn't have to have like any sort
Speaker 1: of keyboard to get it. In fact, that was that
Speaker 1: was even before computer mouse had become really a commonplace item. Yeah,
Speaker 1: you know, some of those early touch screens, at least
Speaker 1: the ones that I used, were sort of like touched
Speaker 1: touch touch touch, touch, touch, touch touch touch touch screens. Punch, punch, cry,
Speaker 1: mop up blood. Yes, those were the stupid thing doesn't work. Yeah,
Speaker 1: that the technology has improved somewhere, it hasnally. Now, there
Speaker 1: are different touchscreen technologies that that are commonly used today.
Speaker 1: The two most common when it comes to things like
Speaker 1: portable electronic devices, so things like NP three players or
Speaker 1: smartphones or whatever, would be resistive screens and capacitive screens. Yes,
Speaker 1: all right, so let's talk about the differences between these
Speaker 1: two systems since these are the most common that you'll
Speaker 1: find out there a resistive screen or resistive system. It
Speaker 1: consists of several layers of screens. It's like an onion
Speaker 1: of screen. Yes, And the way that the system works
Speaker 1: is when you press upon the screen, you compress these
Speaker 1: different layers together and when they touch, it creates an
Speaker 1: electric circuit. Right. Normally, there are spacers they keep the
Speaker 1: two the layers apart. Right, If those spacers were to
Speaker 1: be damaged and the space the screen were to permanently
Speaker 1: be fused together, you would lose your resistive UH capabilities.
Speaker 1: It would it would constantly be detecting a specific point
Speaker 1: of pressure somewhere on the screen. So those the spacers
Speaker 1: are very important because basically where you're touching it, the
Speaker 1: computer is able to tell basically the coordinates of where
Speaker 1: you're touching, and you know, maps that up to what's
Speaker 1: being displayed on the screen, and that's how it knows
Speaker 1: what you're touching and when. Right, So there's a processor
Speaker 1: that is um it's receiving this information based upon where
Speaker 1: the different layers of the screen are touching, and that
Speaker 1: way it can it can give the correct response. So,
Speaker 1: for example, if you have a phone that has a
Speaker 1: resistive screen touch screen and you're pushing the call feature,
Speaker 1: then it's going to map out the location of the
Speaker 1: touch send that information to the processor. The processor says, hey,
Speaker 1: when this particular area on the screen is touched, that
Speaker 1: means that this action must be performed, and your phone
Speaker 1: makes a call. And this all happens very very quickly.
Speaker 1: Anklebone is connected to the footphone something like that. And
Speaker 1: old resist of screens had a few big disadvantages really
Speaker 1: compared to the other type the capacity of screen. One
Speaker 1: of those was that the the the different layers would
Speaker 1: somewhat obscure the light coming from the screen, so you
Speaker 1: would only get a certain percentage of the light coming
Speaker 1: out of the screen that you would get if the
Speaker 1: if the screen were completely clear or transparent. UM. The
Speaker 1: layers had to be really thin, yes, in order for
Speaker 1: this to work properly, right, and some of them could.
Speaker 1: Some of them could detect things like the amount of
Speaker 1: pressure that you used, and really the amount of pressure
Speaker 1: was coming from not how hard you were pushing, but
Speaker 1: how much surface area of your finger or other whatever
Speaker 1: it was was in contact with the screen. UM and
Speaker 1: that could give it an indication of how hard you're pushing,
Speaker 1: because the harder you push, the more of your finger
Speaker 1: is going to be against the screen. So that whole
Speaker 1: punching thing not really effective. No, that would be a
Speaker 1: bad idea. It's pretty much a guarantee that you're gonna
Speaker 1: break your resistive or any other touch screen. UM. The
Speaker 1: the other disadvantage was that early resistive screens couldn't do
Speaker 1: multi touch. Um, they were not capable of of accepting
Speaker 1: two different points of contact at the same time and
Speaker 1: could not interpret that as a you know, a legitimate command. Now.
Speaker 1: Of course, we've got a lot of devices out there
Speaker 1: that support multi touch now, and most of those are
Speaker 1: using capacity screens. However, I can report it is possible
Speaker 1: to create a resistive touch screen that supports multi touch.
Speaker 1: You have to create a system that specifically supports this.
Speaker 1: You know. It's not just like any resistive screen could
Speaker 1: do this with a firmware update. You'd actually have to
Speaker 1: go through the manufacturing process. But engadget has a video
Speaker 1: on their site of a pretty cool device. Um. It
Speaker 1: really was a concept of prototype where it's resistive screen,
Speaker 1: it can detect pressure, and it is uh, it can
Speaker 1: detect multi touch. One of the advantages of the resistive
Speaker 1: system to the capacitive system is that you don't have
Speaker 1: to You can use pretty much anything to contact the
Speaker 1: screen and and give a command. So it doesn't have
Speaker 1: to be your finger. It could be a stylist, right,
Speaker 1: it could be anything, because it could be a dog. Yes,
Speaker 1: it could be a rock, it could be some play doh. Um,
Speaker 1: it really doesn't matter because as long as it is
Speaker 1: able to make that pressure against the screen, that's going
Speaker 1: to count as a an input. Now, capacity of screens
Speaker 1: are different. Now they actually have a layer that stores
Speaker 1: an electrical charge in them. That would be the capacitance layer. Yes,
Speaker 1: Thus the name kind of makes sense now, doesn't it amazing,
Speaker 1: isn't it. I mean the capacitive layer is uh, you know,
Speaker 1: storing a like Tron's right, So it's storing these electrons
Speaker 1: right there on the screen. When your finger comes in
Speaker 1: contact with the screen, this actually ends up transferring the
Speaker 1: charge to you. So technically you are kind of getting
Speaker 1: a very mild shock. I find that revolting. Do you
Speaker 1: do you get a charge out of it? We can
Speaker 1: do this all day, palass oh, I know, and and
Speaker 1: our listeners are depart like lightning was especially a shocking
Speaker 1: kind of experience as long as you stay current. But
Speaker 1: you know, I could tell that my iPod Touch has
Speaker 1: a capacity screen because I'm stopping because you know, sitting
Speaker 1: out and waiting for the bus or the train to
Speaker 1: bring me to work here in the morning in the wintertime,
Speaker 1: and having gloves on. You can't change you know, the
Speaker 1: volume on your iPod because you know, my bears get
Speaker 1: you know, the gloves won't because they start for the chart.
Speaker 1: If they don't, they don't, they won't pick up the
Speaker 1: charge like your skin would if you are But otherwise,
Speaker 1: if you if you are outside on a really cold,
Speaker 1: dry day, you might have problems getting a capacity of
Speaker 1: screen to work at all. Uh. Capacity screens work best
Speaker 1: when there's at least a little bit of humidity to
Speaker 1: help conduct that electricity. Right. Yeah, but if it were
Speaker 1: really called dry day, you might find that your touch
Speaker 1: screen is not very responsive. It's not necessarily because your
Speaker 1: phone is cold. It may be because you don't have
Speaker 1: the moisture on your finger that helps create that that
Speaker 1: electrical connection. And um, we'll see. That's good because I
Speaker 1: like licking my iPod, So that explains why it always
Speaker 1: works pretty well. Also explains why I have the swine flu.
Speaker 1: So anyway, the capacity of screens actually do support multi
Speaker 1: touch if you create the right hardware and software around it.
Speaker 1: They don't automatically. It's not like magically supports it. You
Speaker 1: have to build the system around it. Um. And of course,
Speaker 1: if you were to build the system around it, you
Speaker 1: could very possibly engender the wrath of Apple because they
Speaker 1: patented it. They patented multi touch for for mobile devices.
Speaker 1: That was really smart of them. It's also incredibly mean
Speaker 1: because the Android operating system actually supports multi touch, but
Speaker 1: it is not um enabled in any Android device that
Speaker 1: I know of. Specifically, I assumes the patent I should have. Yeah,
Speaker 1: I should assume it's because of this patent, and if
Speaker 1: if the phones were to support multi touch, then it
Speaker 1: could very well be Even if it's not directly in
Speaker 1: violation of the patent, I'm sure that an argument could
Speaker 1: be made and then you've got a costly legal battle.
Speaker 1: So that would be why the iPhone is this great
Speaker 1: multi touch device and most other devices don't support multi
Speaker 1: touch in the same way. Um, some of you may
Speaker 1: be yelling, hey, what the Microsoft surface. We'll get to that.
Speaker 1: It's a it's a totally different animal. But the capacitive system,
Speaker 1: so you know, like I said, it's it's it detects
Speaker 1: this electrical uh connection, and that it's in a way
Speaker 1: does the same sort of thing as the resistive screen
Speaker 1: in the sense that it finds out you know, it
Speaker 1: says where the connection happens on the screen, it maps
Speaker 1: that to a specific command, and then the processor executes
Speaker 1: that command. So the big difference between the two systems
Speaker 1: is how it how the electrical connection is made. Yeah,
Speaker 1: basically the one Once the the circuit or you know,
Speaker 1: is completed and an electrical connection is made, the computer
Speaker 1: on the other end figures out where it is and
Speaker 1: what it's supposed to be doing at that point, right,
Speaker 1: and and again with capacity of screens, you would have
Speaker 1: to use something like a finger or you know, your
Speaker 1: nose or you know, something that could create could accept
Speaker 1: this charge from the screen. You couldn't use something that
Speaker 1: was passive like a stylus or the rock four mentioned rock. Right,
Speaker 1: you could possibly use a dog, depending on what part
Speaker 1: of the dog was touching the screen. Yeah, yeah, you know,
Speaker 1: or nose or something. But well yeah, well some of
Speaker 1: us can leave a lot of finger smudges already, so um.
Speaker 1: But yeah, if you wanted to use a stylist with
Speaker 1: a capasity screen, you would have to have a stylist
Speaker 1: had an active point on it that could accept that charge,
Speaker 1: otherwise you wouldn't get anything out of it. So that
Speaker 1: actually makes me wonder what the Microsoft Courier tablet, the
Speaker 1: prototype that we we We've seen a video that was
Speaker 1: more or less an animation of this prototype tablet that
Speaker 1: Microsoft is coming out with. It's got two screens and
Speaker 1: it has a touch screen interface, and it shows people
Speaker 1: flicking through with their wealth. It shows an animation of
Speaker 1: a finger flicking through pages UM and it also shows
Speaker 1: an animation of like a stylist writing on a page.
Speaker 1: So I kind of wonder what kind of touchscreen technology
Speaker 1: it's playing on using if if they're using going to
Speaker 1: use resistive or they're going to use capacitive UM. There
Speaker 1: is another choice, but you don't see it that often
Speaker 1: in in smaller devices. Is the surface acoustic waves system. Yeah.
Speaker 1: Now this is something that you would see in and
Speaker 1: more often in things like a t M S and
Speaker 1: bigger displays. But what this uses is a couple of
Speaker 1: transducers and they are placed along the X and y
Speaker 1: axes of the glass plate of the monitor, and whenever
Speaker 1: it sends an electrical signal, one transducer sends it to
Speaker 1: another transducer, and there are reflectors on there to kind
Speaker 1: of reflect the signal from one to the other. When
Speaker 1: something makes contact with the screen, it disturbs that electrical wave,
Speaker 1: and by measuring the disturbance, the touchscreen knows where it
Speaker 1: was touched that. When I say knows, of course, we're
Speaker 1: talking about a processor that that that the screen. Yeah,
Speaker 1: the screen itself does not know. Um, it's not magic,
Speaker 1: and it doesn't it's not sentient. It's once touch screens
Speaker 1: become sentient, sexual harassment lawsuits will go through the roof
Speaker 1: because of inappropriate touch screen interface. Let's we'll see if
Speaker 1: that stays in the right. At any rate, the surface
Speaker 1: acoustic wave system UH is not often Now, for one thing,
Speaker 1: the equipment that you need in order to make this
Speaker 1: thing work is kind of um big. It wouldn't really
Speaker 1: be easy to miniaturize this into a mobile format, right,
Speaker 1: So you wouldn't want to try and use this kind
Speaker 1: of technology in your in your general mobile device because
Speaker 1: it would make it too fat, too heavy. Um. And
Speaker 1: of course we all want sleek and stylish. Well, I mean,
Speaker 1: you know, the iPod pretty much proves that the sleek
Speaker 1: and stylish approaches is really popular. I mean, it's a
Speaker 1: good product anyway, but I think that the style is
Speaker 1: definitely a large contributing factor to the popularity of the
Speaker 1: iPod line. So at any rate, uh, capacity of resistive,
Speaker 1: that's the two that you're going to see the most
Speaker 1: often in your in your average mobile devices. Um, the
Speaker 1: iPhone uses a capacity of screen, and like we said before,
Speaker 1: it actually can detect multi touch. So that means that
Speaker 1: you can use gestures instead of just touching. Two give
Speaker 1: commands things like pinching, you know, like if you pinch. No, not,
Speaker 1: I'm not actually pinching, Pillette. I want to make that clear.
Speaker 1: I've already made one sexual harassment. I am not. I
Speaker 1: am not even within pinching range of palette. Um, he
Speaker 1: has barricaded himself in the corner and he's perfectly safe.
Speaker 1: I got my blanky. Yes, he does have his blankie. No.
Speaker 1: But but you know, like like when you wanna when
Speaker 1: you want to squish or enlarge a photo doing various
Speaker 1: pinching motions, or if you're panning or whatever, these are gestures. Okay,
Speaker 1: But so these are commands that your phone should or
Speaker 1: m P three player or whatever should be able to
Speaker 1: recognize as a very general command as opposed to open
Speaker 1: up this application I want to use it. It's more
Speaker 1: of a you know, I'm I'm manipulating something, rotating a picture,
Speaker 1: or you know, scrolling from one screen screen to another,
Speaker 1: that kind of thing. And UM. I mean, regular touch
Speaker 1: screens can identify some gestures as well. It's just multi
Speaker 1: touch can identify more complex gestures. Uh. So that's pretty
Speaker 1: much the the basis there. I mean, the the both
Speaker 1: kinds of display are both kind of touch screens are
Speaker 1: fairly accurate if they're done well. The execution has to
Speaker 1: be there. But there's nothing about either u I Their
Speaker 1: technology that makes one far more accurate than the other. UM.
Speaker 1: They're both challenging to do well. But if you do uh,
Speaker 1: you know, if you do the good work, then either
Speaker 1: one should be more than accurate enough for the average user. UM.
Speaker 1: The resistive screens are much cheaper than capacitive screens. UM
Speaker 1: capacity seems to have the probably more support among the
Speaker 1: technology savvy crowd. They seem to like the capacity screens more,
Speaker 1: probably because of things like the old resistive screens were
Speaker 1: harder to it's harder to see the images they were scratched.
Speaker 1: They weren't scratch proof that they could get scratched pretty
Speaker 1: easily because the screens had to be soft enough for
Speaker 1: you to press them in a little bit. UM. But
Speaker 1: if you're concerned with manufacturing a device that's going to
Speaker 1: be an inexpensive one for your customers than the resistive
Speaker 1: screen is a more attractive approach because it's less expensive
Speaker 1: for those components. If you're doing a premium product, capacitive
Speaker 1: it is probably the way to go. Yeah, well, it
Speaker 1: seems like, you know, over the past few years, with
Speaker 1: the ubiquitous nous of these devices, it's you know, it's
Speaker 1: harder to find the implementation done poorly. He thinks that
Speaker 1: more and more people are getting it right, which is
Speaker 1: what's making you know, applications for these devices more and
Speaker 1: more common. And a lot of the problems with touch
Speaker 1: screens have more to do with the underlying operating system
Speaker 1: than the technology of the screens themselves. So like older
Speaker 1: operating systems for smartphones are tend to tend to have
Speaker 1: a little more trouble with touch screens than the more
Speaker 1: recent ones. You might have an older phone that's running
Speaker 1: an older version of Windows Mobile, for example, that UH
Speaker 1: is not as responsive as newer versions. UM. I think
Speaker 1: Microsoft philosophy right now is from now on going forward,
Speaker 1: smartphones running running Windows Mobile will have resistive screens. Smartphones
Speaker 1: that will run the Windows Mobile or the Windows seven
Speaker 1: modified modified UH operate system for mobile devices will have
Speaker 1: multi touch and will be capacitive screens. So that's kind
Speaker 1: of interesting that they've actually developed two different strategies that
Speaker 1: and each one focuses on a specific technology. Well, it
Speaker 1: makes sense that they would try to keep the cost
Speaker 1: down by using a resistive screen in a you know,
Speaker 1: more consumer device and higher end screens. Yeah, it's it's
Speaker 1: actually a pretty clever approach. I think it'll be interesting
Speaker 1: to see how that plays out. The only thing I
Speaker 1: could think of that might cost them more money down
Speaker 1: the road is by having the complexity of having another
Speaker 1: system and another device, and it's another thing they have
Speaker 1: to tool up for and another thing they have to support. Yeah. Well,
Speaker 1: they've also got issues with their their Windows Mobile store,
Speaker 1: and there there are a lot of things that the issues,
Speaker 1: a lot of things Microsoft look at. Yeah, never any
Speaker 1: issues with technology. I was going to mention also that
Speaker 1: Research in Motion also known as risk Yes, the the
Speaker 1: company behind BlackBerry. They filed a patent in January two
Speaker 1: thousand eight for a hybrid resistive capacitive screen would have
Speaker 1: both resistive and capacitive layers. I tried reading this patent
Speaker 1: to figure out how it would work for this podcast,
Speaker 1: and I think I would need another three or four
Speaker 1: days to really get through it to understand it. Um.
Speaker 1: I can't even pretend to go into the science behind
Speaker 1: it because part of it is written in Martian. Well,
Speaker 1: it's written in patent ease and okay, so it's a
Speaker 1: level of difficulty above Martia. It's slightly more difficult than
Speaker 1: Martian UM. And then I said, we were going to
Speaker 1: talk about the Microsoft Surface very quickly. So the surface,
Speaker 1: it doesn't use a capacitive resistive It does not. It
Speaker 1: is if you don't know what it is. It is
Speaker 1: a table like device. It has a monitor on the
Speaker 1: top of it, so you would sit down at one
Speaker 1: of these things, and it has a big screen that
Speaker 1: you can touch and manipulate things on the screen. You
Speaker 1: can have images there, you can play games, and it
Speaker 1: can detect dozens of different touch points, so it's not
Speaker 1: just you know, two finger touching. You could have a
Speaker 1: game where five people are sitting around this table and
Speaker 1: are playing a little pinball game or whatever, and each
Speaker 1: one's controlling a set of flippers, you know, or tons
Speaker 1: of other different implications. It does not use capacity or
Speaker 1: resistive touch screens. Instead, it uses cameras and an image
Speaker 1: recognition UH software that is in the infrared spectrum. So
Speaker 1: these cameras are pointing up from inside the device. They're
Speaker 1: pointing up at the screen, the screen surface, and they
Speaker 1: detect the points of contact and then send that information
Speaker 1: to the processor, which then you know, translates into a command.
Speaker 1: The neat thing about this is you can use multiple
Speaker 1: objects on the surface and and automatically transmit commands. So
Speaker 1: let's say that you have a an MP three player
Speaker 1: that can wirelessly sink with a computing device. So let's
Speaker 1: say you've got a Microsoft Zoom and you lay this
Speaker 1: down on the surface, the surface, the surface of the surface. Yes,
Speaker 1: you could lay it on the screen of the surface,
Speaker 1: and you could sink your device with the surface automatically
Speaker 1: just by laying it on the screen, because it would
Speaker 1: detect the shape and size of that Say, hey, you
Speaker 1: know what that is. That's a zoom uh, and it
Speaker 1: just automatically has the command that when that device is
Speaker 1: placed on there, it'll sink. Yeah. So there are a
Speaker 1: lot of interesting swine flu interesting um applications for this device.
Speaker 1: So anyway, that was one thing I wanted to bring
Speaker 1: up because technically that's not even if you think of
Speaker 1: it as a touch screens. It's not really a touch screen.
Speaker 1: It's really all because the camera. You had a similar
Speaker 1: device you wanted to mention briefly, right, Well, yeah, because uh,
Speaker 1: you know, as we were talking before hand, I started
Speaker 1: thinking about other devices like that UM and uh one
Speaker 1: of the ones that our friends that stuff from the
Speaker 1: B side uh recorded And actually John Fuller wrote about
Speaker 1: the React table, which uses a series of acrylic shapes
Speaker 1: on a Microsoft surface like surface UM to control music.
Speaker 1: And I started thinking about how that worked, and you said, basically,
Speaker 1: it's the same, you know, a similar situation of cameras
Speaker 1: underneath the table. And I remember from editing that that yes,
Speaker 1: it's got UM, it's got a screen on which the
Speaker 1: shapes said, and it's you know, the cameras tracking where
Speaker 1: those those different pieces are. And it says, okay, well
Speaker 1: this is a this is a circle. I know, you
Speaker 1: know when his circle it controls the beat is you know,
Speaker 1: the square does this. So that's uh yeah, So depending
Speaker 1: on the position of those and the position and configuration
Speaker 1: right those different objects, it'll create a different set of
Speaker 1: sounds and you can rotate things in it, you know
Speaker 1: it because it's the shape and the position of the
Speaker 1: uh implement that it has to do a certain thing. Yeah,
Speaker 1: I've seen similar applications which would do things like even
Speaker 1: incorporate stuff like colors, so you might have a one
Speaker 1: circle that's blue and one circle that's red, and it
Speaker 1: actually translates to two different commands, so you can have
Speaker 1: multiple circles on the same sort of surface and and
Speaker 1: it would Yeah. Again, mostly it's it tends to be
Speaker 1: things for like music performance art. I think Byork toured
Speaker 1: with one of these, so, um, the thing is, my
Speaker 1: question is if you, you know, have an instrument that's
Speaker 1: using you know, reds and yellows, can it help you
Speaker 1: play the blues? Let's move on. I'm glad that we
Speaker 1: have exhausted touch screen, or at least I'm exhausted. But
Speaker 1: then again, I've got puns aren't helping, I'm sure. Let's
Speaker 1: move on to a little listener mail. This listener mail
Speaker 1: comes from Chase, and Chase is an Oregonian living in Osaka, Japan.
Speaker 1: He's also very verbose. Chase, I loved your email, and
Speaker 1: I responded to Chase already, so I'm gonna have to
Speaker 1: sort of summarize Chase's email here um, but he said
Speaker 1: they had an He has an iPod Touch and he
Speaker 1: got an application called Anti Young Free, which emits a
Speaker 1: sound that only young people or people who took very
Speaker 1: good care of their ears can hear. Because I work
Speaker 1: in a high school, so I decided to test it
Speaker 1: out on the class of fifteen to sixteen year old
Speaker 1: I got them all to stand up and then push
Speaker 1: the button to turn the sound on and told everyone
Speaker 1: to sit down and they could hear something. To my surprise,
Speaker 1: eight of the forty students remain standing and mystified. According
Speaker 1: to the descriptions for this app, people who people should
Speaker 1: be able to hear it until they are around twenty
Speaker 1: to thirty years old. I'm twenty five years old and
Speaker 1: cannot hear it, but my wife, who was twenty four
Speaker 1: freaked out when I turned the sound on. That aside,
Speaker 1: I also discovered a number of other absolute things like
Speaker 1: repel mosquitoes or act as dog whistles. And you wanted
Speaker 1: to know, one, how does it work? And two is
Speaker 1: it doing any damage to his speakers? Let's take the
Speaker 1: second one. First, most speakers can emit sounds that are
Speaker 1: well beyond the range of human hearing, and so they're
Speaker 1: perfectly capable of doing this. Nothing bad is going to happen, um,
Speaker 1: you know, on its own, because that's what speakers do.
Speaker 1: They're capable of emitting these sounds. It's not not like
Speaker 1: it's suddenly ripping itself apart. But the first part about
Speaker 1: how does it work? Well, humans can hear in a
Speaker 1: range of of sound frequencies that it's between about twenty
Speaker 1: hurts and twenty thousand hurts, give or take a few thousands.
Speaker 1: All depends on who you ask, really, but whether you're
Speaker 1: male or female. And of course, as we get older,
Speaker 1: we start to lose the capability of hearing that complete range,
Speaker 1: and in general we lose the upper ranges first. And
Speaker 1: so if you are in your late twenties, early thirties,
Speaker 1: you may only be able to hear up to fourteen
Speaker 1: thousand hurts or sixteen thousand hurts or sixteen killer hurts
Speaker 1: if you prefer. But um so, anything above that frequency
Speaker 1: you just you don't, you don't hear it. But younger
Speaker 1: people could still hear that. And in general, human beings
Speaker 1: don't like high pitched noises. They tend to irritate us um,
Speaker 1: which is you know why Chris likes to drown me out,
Speaker 1: I guess at any rate. So that's how that really works,
Speaker 1: is that as we age, we just naturally begin to
Speaker 1: lose that ability, and some of us lose it more
Speaker 1: slowly than others. So you may find someone who's thirty
Speaker 1: two who can hear the same thing that a sixteen
Speaker 1: year old can hear, or you may find you know
Speaker 1: a fourteen year old kid who can't hear anything at
Speaker 1: all from that particular range. Um, it's very subjective. There
Speaker 1: are no hardened past rules, but in general, if you're
Speaker 1: talking about big numbers, that's kind of how it works.
Speaker 1: So thanks for writing in Chase. If any of you
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Speaker 1: write us tech Stuff at how stuff works dot com.
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Speaker 1: the blogs over at how stufforks dot com and Crispy
Speaker 1: and I will talk to you again. Hopefully I will
Speaker 1: be talking without a raspy voice really soon. For moral
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