The Future of Sound: Part One

sound bizarre. On the other end of this, I don't you know, you never really tell what you yourself sound like. People. You are sounding a little bit more of vibrato than usual, Well, that may just be my opera singing that I've been practicing. On the side, we're also recording earlier in the day than we usually do, so that could affect our sound. That is, I'm actually really surprised that I don't sound like Tom Waits right now. Usually usually before like one pm,

the microphones have been drinking. Yeah, whenever, whenever I think about the future of sound, the thing that I hope that they come up with is a device that actually makes your voice sound the way it sounds in your head, so as you sounds as good as you do inside of your your head, as opposed to listening back to a recording and thinking, oh, that's not what I sound like, is it. Yeah, Today, we wanted to really look into

different uses of sound. I mean, sound clearly is a very powerful thing, and in multiple ways, Like it can be figuratively powerful, like you hear something truly moving and you have an emotional response to it, or it can be physically literally powerful, like the shock way from a sonic boom, which can shatter glass or even knock you over depending upon the power of it and how close you are to the shock wave. I mean, it literally

has physical power. So we're gonna really look into some cool uses for sound in the future, and we have so many of them that this is the first part of a two part episode. Thank you for pointing that out, Law, and so we don't remember halfway through and then go have to go back and say that all over. That's right, So we've got a lot to say now. The video episode that goes along with this, this pair of audio podcast I cover three interesting things about sound in the future.

And we're gonna go more in depth on all of those as well as additional ones, because, as I said in the video, there's so many potential uses and things that we're learning about sound that it's really the stuff I talked about in that episodes, just the tip of the iceberg. But before we get into all of that, I think it would be beneficial for us to actually learn what sound is, how it works, because that will go on to inform, uh, the other stories we talk

about and how we're making an innovative use of sound. Right, So, sound is the magic produced by the music of the sphere vibrating on the fourth harmony. You watched that April Fool's episode of for Thinking way too many times? Um, Yes,

the character from that episode would certainly agree with you. However, if we want to get a little more scientific, Yeah, we're talking about sound being that's that's what's produced when stuff, when matter vibrates, all right, that's that's your basic definition. When matter vibrates, it produces sound. Whether there's anyone there to hear it, who's to say so if a tree

falls in the forest, it does make a sound. You might not be there to perceive it, But it happens um So stuff vibrates at certain frequencies which are completely determined by the physical properties and the parameters of that stuff. This is called the resonant frequency, right Like how dense it is or the temperature of the of the matter can can determine it. The actual physical structure, whether it's a crystalline structure or not, that can determine it as well.

If you're talking about air, like the humidity, the water content, and exactly so when we talk about the speed of sound, which will get more into in a little bit, little tiny things can make a difference. Now it might not be perceptible to we mirror mortals because we're not capable of detecting millisecond you know, differences in speed, but the altitude, the density of the air obviously would go along with that. That has an effect. The temperature, the humidity, all of

these things can affect the speed of sounds. So when something vibrates like a drum, if you strike that drum, it's gonna vibrate at its resonant frequency. Same sort of thing like if you tap a glass and they hear that little tinging sound, it's going to be vibrating at that resonant frequency, and that sound will be consistent. So if you hit it again, it's going to make that same sound unless you change the parameters of that object.

So like with a drum, if you were too tighten or or loosen the drumhead, you would get a different sound the next time you strike it because you've actually changed the physical parameters of that matter, or if you strike it with a different stick, different speed. Technically, the actual frequency of the sound should be more or less the same. Now, the amplitude will be different, but the frequency at which it vibrates apart from the initial contact.

When the initial contact happens, you're actively introducing a bit of a random event to that matter, but it will settle into the frequency. Because it's really easy to make matter vibrate at its resonant frequency and really hard to make it vibrate at any other frequency. It's one of the things about resonance that's really interesting. Now you can do it, but it takes more effort, and as we know, based upon the laws of physics, things tend to kind

of move to the easiest state. Right if it takes more energy than interpetes like no, no, no, no, no, no, no, I was kind of thinking about the difference between drumming with sticks and drumming with brushes. Sure. Yeah, Now, the actual frequencies, if you got down to a point where you were measuring the sound waves, you would see that the frequencies would be really very similar. It's just that you're generating them in a different way. So to us it sounds different, but the when you get down to

like actually looking at wave forms, it would be very similar. Um. So these vibrations that we we are talking about, that's not It's not like something vibrates and then magically we can detect it. Other stuff has to happen for us to be able to perceive those vibrations. And generally what we're talking about is come pression and rare affection of air molecules. So, because as we've stated before, air is not empty, right, it is stuff, it's molecules. It's more

like a soup. It's more like a soup that we just hang out in all the time. Yeah, it obeys the laws of fluid dynamics. Delicious nitrogen soup. Yeah. If there weren't that stuff, we would be in a vacuum and wouldn't be talking right now, because we'd be unable to generate sound or breathe. But you know sound on the same principle you've heard behind when you hear a nerd get mad that while in this movie something blew up in space and you heard it and you're not

You really shouldn't be able to hear it. Yeah, if you were in the spacecraft, you would probably hear something. For all the air escaped. Every spaceship is miked extensively. Yeah, maybe it's and that's what the filmmakers are using. Yeah, it's just that whatever whatever space camera is on, that just automatically adds in the sound of an explosion, because

otherwise is are a little tiny human brains would crack. Um. So when when the vibrations are moving, that causes the air molecules to move in this process of compression and rarefaction. That's essentially when air molecules are pressing together and then spreading apart again. Now that causes the adjacent air molecules to move, and so on and so forth until you go from the source of the sound to an ear drum.

So when we're talking about the perception of sound, which from us, for we humans tends to be through hearing, but you can actually receive sound also through you know, you could have a tactile sensation, you could feel sound. But when we're talking about hearing, those air molecules end up impacting our ear drums. Now, our ear drums are really important. And it's a membrane that's attached to a series of three small bones that are in our middle

ear that act as an amplifier. So your ear drums starts to vibrate, these three small bones essentially amplify that and they end up transmitting those vibrations to are to the cochlea which has this fluid in it and little tiny read like uh fibers, I guess you could say. Yeah. And those hair quot marks in the air, they're we're really useful on audio. And those hairs have specific resonant frequencies.

So certain hairs will start to vibrate depending upon the motion of the fluid, and other other hairs won't vibrate because the resonance won't match up, you know, the rather, the vibrations won't match up with their particular resonance, right, And so the the hairs when they vibrate will send a signal like like pop off a little neuron to your brain saying like, hey, this hair vibrated, and your brain amasses all of those signals from those hairs to say, oh,

this is what this thing sounds like. Right, So the sound you are hearing right now as you listen to this podcast is actually your brain interpreting those little vibrations of reads and then sending little electrical impulses and then there you go. So it's kind of cool and weird also in a way to think like, oh, sound is something that largely is happening inside my head. Like I know that there actually is a physical manifestation of sound because we have but but but ultimately our perception is

all in the head. It's not like if you take the brain out that, uh you know, what would that sound be like without that particular process. Who can say that's not how we are, Like all reality is like a dream man. Yeah, Yeah, that's toads where I was going with that. So when we talk about about actually measuring sound, there are three things we typically look at, which are the frequency of the sound, the amplitude of

that sound, and the wavelength of the sound wave. Yeah, and one thing that makes this kind of difficult with sound is that you usually picture these three variables in terms of a transverse wave like light or like the waves in the ocean shan, where the oscillation of the wave is moving perpendicular to the motion of the wave. So like you've often seen a picture of a wave, it's little hoops going up and down along a central midpoint, and sound is sort of the exception to that type

of wave of motion. It's not really like that. It's a compression wave. It radiates outward from the source of the sound as well, so the oscillation is going parallel to the direction of the way right, and it's three dimensional, But we do use that two dimensional representation of waves to to look at sound waves because tiny delicate human brains. Yeah, it's way easier, it's useful. Yeah, it ends up being a useful way to describe the behavior of the sound waves.

And it's not that the like technically you could say the depiction is not truly correct in the sense of the way the waves behave, but it ends up being useful for talking about things like um in versus, like an inverted sound wave, and uh, you know, when you pair it with the original sound wave what happens. Uh. So, frequency is what we would normally associate with pitch, right, technically, I mean it's it's this is the easiest way of

saying it. The higher the frequency, the higher the pitch. Now, human hearing has a range of frequencies that typically we can detect. Now, this is typical in the sense that there are people who have a hearing range that can go a little further outside of it, and there's some people who it's narrower and um, typically we talk about it being from twenty hurts, which is twenty cycles per second. So that would be the frequency of you know, when

these waves would pass. Uh, twenty of those cycles in the second would be one hurt or twenty hurts rather or up to twenty killer hurts, which is twenty thousand cycles per second. Uh. Again, that's a general rule of thumb. Some humans can hear outside of those ranges, and some are are are limited to a much narrower range. And and really the range that we hear best in is one killer hurts to about four killer hurts. Yeah, that that tends to be the range we mostly encounter. And

are you know, like the range of human voices. It's what we work in daily. Yeah, what is the singular of killer hurts. It wouldn't be kill a hurt It's it's still hurt hurts because hurts is named after Hurts named after a person. But you don't say hurts is right, Yeah, it's it's four killer hurts is. It's like, dear, I'm going to start saying that from now on, you're being kill a hurtful all right? Anyway, moving on, always say

it at one hurts all right. Now, obviously, you can have frequencies outside the range of human hearing, and these frequencies can still have a physical effect, and we will talk about any of those when we get into the future uses of sound. Yeah. In fact, a lot of times we specifically want to use frequencies of sound outside the range of human hearing. Yeah, because if you're using it within the range of human hearing, it could be

really irritating depending upon the application. Right. Uh So, next we have the amplitude. So if you picture the transverse wave, right we were talking about, that's going to be the distance between the midpoint and the crest or the trough of the wave, and uh, amplitude essentially ends up being perceived as volume. So the greater the amplitude, the louder the sound. So your your frequency determines the pitch, the

amplitude determines the volume. Then you have wavelength. This is the distance between two analogous points on two successive waves. So you pick a point on one wave, you pick essentially the same point on the next wave, and you measure the distance between the two. That is the wavelength of the sound wave. Very often you could just say it's crest to crest, right. So this depends upon the frequency and the medium through which the sound is traveling.

Wavelength can vary even within the air, again, depending upon that temperature of the air or the humidity or the density of the air. Um and wavelength of frequency are inversely proportional to one another, So if the wavelength of a sound wave increases in uniform medium, the frequency decreases. So uh, this is important when you're starting to figure out things like the speed of sound through any given medium.

If you know the frequency and you know the wavelength, then you multiply the two together and you get the speed of sound. And it also comes into effect when we're studying things like the Doppler effect, where the extension or the compression of waves can affect the frequency right. Uh. Now, we also need to talk about how sound waves can interact with each other because they could do some pretty

interesting things. If you get two identical sound waves played together, they can amplify one another, so their amplitude can be uh additive. If you end up getting a sound wave where it encounters its inverse, they cancel each other out. This is the way noise canceling headphones work. They attempt to create an inverse wave that would end up canceling out all the noise that's around you, creating like a

little pocket of of dead sound air. Yeah, that's the goal if they if they are working properly, Um, you know your your mileage may vary depending upon the sound

canceling headphones. Uh. And two different sound waves that mixed together end up creating like if you were to look at this this depiction of a sound wave, it would end up looking really super funky because the the the troughs and crests would be affected by each other and you would end up getting a result where if one had a bit of a crest but the other one had a deeper trough, then it's gonna look like, well, now the new sound wave has a trough, but it's

not as deep as from two. Very complex and mathematical and and actually I would totally love to have like a like a sound engineer come on the show and talk about it, because it is whoa like like way. Every time I start thinking about it, my brain just kind of goes It's it's also way easier to explain if you have the the visual aids of nearby, and

then we do not obviously as an audio podcast. So and it's kind of funny that you need visual aids to explain sound that that is a rather amusing a little I mean, it's I guess it's a less more set version of ironic, don't you think. One more interesting things sound waves can do when interacting with each other is, for example, if you create an interference pattern with the sound wave and its reflection of itself off of a hard surface, you can create a standing wave sound. And

we'll talk about those in a bit too. Yeah, that they come into use in some of the technology, but standing waves are a fascinating thing that can happen with all kinds of wave phenomena in nature, which is Yeah, one of those things that that or might seem counterintuitive at first when you think about like, well, how could how could sound do this thing? But as you learn more and more health sound works, it starts to make sense. It's just based upon what what we can directly observe

in our day to day lives. It seems really like, wow, that's magic. Yeah, yeah, although it's not. I mean at a at a more macro level, we've all experienced a sonic boom, right, and and so we have some kind of experience with what sound is this physical force? Right that shows that this isn't just all in your head. Even though the perception of sound maybe in your head, there's the you can physically feel sound like from a sonic boom. You can feel that shock wave hit um

and uh. You know this is something where it's that compression and rare affaction. You can't get that wave coming out from a big event like a sonic boom. It can do some damage, like remember when the meteorite passed overhead of in various aerias in Rush, where there were towns that were reporting that there were entire buildings that add a face of the wall, all the glass just shattering because that that pressure wave was so powerful. So sound is definitely something that can have a big impact,

literally a big impact. Now, we talked a little bit about the speed of sound. That sound travels at a uniform speed depending upon the medium through which it travels. So if you want sound to travel faster or slower, really all you can do is affect the medium. You can either transition it from one medium to another, or

you affect that those physical parameters of the medium. You can't do it by increasing the frequency or the wavelength because if you if you make the frequency, if you increase the frequency, the wavelength will decrease because they're inversely proportional. If you increase the wavelength, then the frequency will decrease

again inversely proportional. So the only way you can make the sound travel at a different speed, because remember that's the product of wavelength and frequency, The only way you can make the sound travel at a different speed is to change the medium in some way. So that's kind

of interesting too. Now that might mean transferring it from one medium to another, like a solid to a gas, or one liquid to another liquid, or anything along those lines, or it might mean that you physically change the medium in some way, um you create you know, like if you increase the tension on a drumhead, technically you're stretching

everything out. That changes the nature of that matter. So, uh, that is important to remember as well, because knowing that the sound of the speed of sound is going to be constant gives us lots of opportunities to use sound in super cool ways. Right Yeah, what once you once you batten down a single variable in a scientific experiment, of course, that gives you a lot of opportunity to

play with the others, right, right. So one of the ways that people are going to be most familiar with using sound as a sort of like novel technological tool will be in medicine. Yes, I mean many people have themselves undergone an ultrasound right yeah, yeah, it's pretty common. Yeah, it's very common. So you can have like ultrasound imaging as a way of like getting a look at what's

inside your body. A lot of times this will be done during a pregnancy or to try to diagnose you know, gall bladder stones or any kind of thing like that, or you could use it as a tool, say to for example, dissolve kidney stones. But there are lots of new ways that people might be using ultrasound in medicine, for example, even in diagnosing cancer. Yeah, and actually ultrasound

is currently being used in diagnosing cancer. I'm going to talk about a super fancy sound method in a minute, but let's let's talk about this ultrasound specifically as it relates to cancer, because it is so fascinating to me. Okay, So various imaging method these days are used to screen for tumors within a patient's body, And it's pretty cool that we have imaging methods because, uh, they're really good at detecting cancer in its early stages before it's done

too much damage. They're all pretty new. Like previous to the late nineteen sixties, tumors were basically discovered by either looking at them or poking them, and that's almost the technical term really, or just like waiting until the patient symptoms developed to the point that a doctor thought it was worthwhile to cut them open and see what was going on. And that's the other way in which imaging is cool, of course, as a screening method, because most

forms of it are pretty safe and non invasive. From the nineteen twenties to the nineteen sixties, a few tests were developed that could detect cancerous or pre cancerous cells from like membrane swabs or urine or fecal matter, but it wasn't until the late nineteen sixties that researchers developed mammography, which of course is a specialized X ray method for viewing breast tissue that became the first widely used imaging method for cancer. But in the early nineteen eighties, researchers

began developing other imaging methods, starting with ultrasound. Uh yeah, so it was first used in the detection of prostate cancer, though it's since been found to be no more accurate than a classic touch based digital examination from a trained doctor, and these days, ultrasound is mostly used in combination with other tests like like mammograms or blood tests or biopsies, in patients that have particularly high risks of developing cancer, or when other methods wouldn't be as effective due to

some other physical factor about the patient's body, or when doctors aren't sure whether a lump is assist or tumor and they don't want to jump straight to biopsy. And what you may be asking is how can as ultrasound possibly tell the difference between assistant a tumor, and that is going back to the speed of sound. Assist is liquid filled, so a sound wave will bounce off it, or sound wave will interact with it differently than it

will with a solid tumor. So let's talk a little bit about how this this actually works in your body.

It's considered really safe. You know, it's just sound waves, so there's an extremely low risk of any harmful side effects, and it's super cheap compared to like computerist tomography or m r I. It's not as detailed, I mean, and the downsides of ultrasound used in medical applications is that it's it's hard to get good images through a lot of fat tissue, and it's impossible to get images through uh like air filled lungs or dense bones or anything

like that. So ultrasonic waves are are really high frequency

sound waves. And therefore ultrasound is a form of scenography that that uses these things that are that are just way above the human hearing level, like like one to one point five mega hurts hurts millions of cycles per second, right right, um, And I mean y'all know how how sonar works, Yeah, You've got a transmitter and receiver that sends out a sound wave, receives echoes of that wave once it's bounced off of an object, and then determines how far away the object is based on the time

it took for the echo to return, uh, and the speed of sound through the medium in question, air, water, or your body, or et cetera. UM. So ultrasonography is is sonar just turned up to eleven? Uh? You can? You can? You can use what's called a transducer probe.

And and and that's the that's the kind of stick or like mouse looking thing that you might have seen or or had used on on you during an ultrasound um and and it can send out millions of ultrasonic pulses every second the sound waves bounce off of the different kinds of tissue in the patient's body and back to

the probe. And the probe is sensitive enough and the computer it's attached to is clever enough that it can track and collect those millions of signals and turn them into a real time image of the surfaces that the waves are reflecting off of. Because we can track the time the waves took to get back, and we know how fast. The waves travel through different tissues muscle, bone and fat and tumors and etcetera, So a tumor will

look different than the surrounding tissue. Interesting also, you know, And just to to kind of add to that, not for ultra sound, but for sonar. One of the other cool things is what we mentioned earlier, what Joe mentioned about about the Doppler effect. You can even with sonar, tell if something is moving towards you or moving away from you based upon the nature of the sound wave that echoes back. Again, not really relevant and ultrasound, but one of those things that one of the other main

uses of sound. Not just by us either. There are a lot of creatures that use ultrasound like echolocation. So all of this is really cool, But the biggest danger of cancer isn't from a single tumor itself, but from metastasis. That's when cancer spreads from one tumor site to somewhere

else in the body. And the way that this happens is when cells or very small clusters of cells break off from a tumor and get into the bloodstream or the lymph system and travel to another part of the body and begin multiplying there or or spurring abnormal growth annunciation, yes, sound waves. So these these cells are called circulating tumor cells or CTCs, and they cannot be detected by ultrasound or even the more sensitive imaging methods like m r

I or CT scans. Now, these cells were first hypothesized all the way back in nine but their exact capacity and really the entire process of metastasis has been a subject of study and debate ever since then. The current popular theory says that CTCs are basically cancer stem cells, which I mean, I mean, it's really it's really fascinating. It's it's one of those things that I get so excited about and then feel really bad about being so excited about. I feel like, I feel like Egon, You're

like Ian Holme and Alien. I admire its purity exactly. Um So, despite the fact that we don't really know what's going on with ctc s, it's pretty safe to say that it would be cool to be able to detect them in the blood stream of a patient with a tumor in order to inform advice on further treatment of that tumor and to recommend future screenings. But they

are really hard to find. You can only expect to find like one ctc per billion blood cells and a sample, and you said that we can't currently find these with ultrasound or any other imaging method that is correct. The ways that we currently have to detect them um usually either will damage the CTC, which sucks because then you can't study it further, or just just they're not very effective.

And we do have some acoustic separation methods for getting CTCs out of a blood sample, but they've satically fallen into that latter category that the technology just hasn't been good enough. The devices used have been slow and awkward and kind of finicky, but acoustic methods don't harm or mark or otherwise mess with the cells, so science has been working on it. Yeah, this is a pretty exciting stuff.

I read this story and originally I was gonna say researchers from but then I looked at all the different groups and there's like six different universities that are all associated with the study. Yeah, I think it was all being headed out of a single university and I did not write it down in the notes. That is a really good tangent um. But but yeah, the fascinating part about the study is that it's it's so interdisciplinary. Yah, it's a combination of cancer research and uh, device creation

and microchips and sound waves. Yeah, you've got engineers, you've got oncologists, you've got all sorts of experts in various fields that all have worked together on this, and uh, it's a little and it's one of those things I say, it's a little complicated, which mostly means that's code for Jonathan sort of but maybe not really understands how this works. But it does come back to that idea that sound

has a physical like exertion, like it can push. Um. So, first, what you have to imagine is a micro fluid I channel, so a very narrow channel. Yeah, this is a device that's maybe about the size of a quarter or so,

like maybe like a half dollar. Yeah. Now it has transducers, which are the things that can convert electricity to sound, all right, So they are used as essentially ultrasonic emitters, and the transducers collectively produce what what was called in the study a tilted angle standing surface sound wave, or actually a collection of them sound waves, I should say. Uh, so these are waves that contain points that were called nodes that stands still relative to the rest of the wave.

So you get your your blood sample flowing through this micro fluid channel with the transducers. Uh, they encounter these nodes and anti noodes that exert force through this acoustic pressure, and the pressure ends up pushing the different cells in different trajectories. So the CTCs get pushed off in one trajectory and the blood cells into a different trajectory. Uh. And this continues down the channel, so successive transducers add to that effect. So the initial change in trajectory is

so small that it would be difficult to detect. But because this is happening again and again through this very tiny channel, Yeah, you get this this like microsecond of of sound pushing at something. And eventually, with enough of those little pushes down the channel, the the different types of cells will separate themselves out right. So that way you end up having your blood cells and your CTCs. Uh. And you can actually then really study the CTC and

they haven't been damaged, right right. Yeah, they're ultrasonic waves, so they don't damage tissue as we talked about earlier, and and you can tune the wavelengths to cur to correspond to the size and weight of particular particles. Uh. The these these cancer cells are generally a little bit larger and heavier than red blood cells. Certainly maybe along the along the same size lines of white blood cells. But yeah, what once you once you've sorted them out, Oh,

it's so cool. Yeah, And what I thought was amazing about this approach was that you can tune those transducers. You could develop transducers for specific types of CTCs, right, and that would make them very efficient. However, they discovered that even if you didn't tune them, they were efficient enough, so that was still an incredible gain over other methods. They found that they could capture eight three per cent of the CTCs within a sample, even if the trend

inducers were not tuned to that specific type of CTC. Yeah, they optimized the device for a couple types of cancer cells HeLa cells and MCF seven cells, and those two are both pretty similar in size. But then they ran the experiment with other types of cancer cells and it

worked just as well. Uh. They're calling this method acoustic tweezers, and the team is looking now into how to make these devices disposable because you're dealing with patient blood samples so disposable, mass producible, and keeping the costs down because right now it's a pretty cheap technology. Yeah, so this could be a really huge benefit for uh, for for doctors who are who need to do something like a

liquid biopsy on a patient. Well, that's amazing. But of course that's not the only way that science is pushing the boundaries of our uses of ultrasound into strange new territory. And I love the us the word pushed. Yeah. Yeah, Well, tweezing the boundaries has tweez a verb, yese, tweezing the boundaries of medical science and ultrasound. Because here's something interesting I came across a while back when I was writing

about brain to brain communication. We've talked before on the podcast about transcranial direct current stimulation and transcranial magnetic stimulation. They're these strange methods science have figured out may be able to affect the brain. I think the jury is still out in a lot of ways on like what

exactly the effect is and how useful it is. But they're using electricity or strong magnet electromagnetic forces to cause stimulation in certain like targeted regions of the brain to hopefully produce a desired effect in an experiment and without the need for invasive surgery. That's the transcranial part. Yeah, so you don't have to open person up and put electrodes inside the parts of their brain that you want

to mess with. Yeah. We talked about this about how some people were doing it to themselves with small like electrodes attached to their temple. And we're not recommended to try this at home, folks, but yes, some people out there do think it makes them smarter if they hook a nine volt battery up to their scalp. It's odd

I feel smarter about not detching ninevola um. But there's another method actually is out there for non invasive brain stimulation, and instead of being based on electricity or electromagnetism, this is based on ultrasounds. It's known as transcranial focused ultrasound. Right. H There was a paper that was published in and Nature Neuroscience that was all about experimentation in this research

into this field of using ultrasonic frequencies. So very similar in in many ways to the methods that Joe was just talking about, except instead of using magnetic fours or electricity. You're using very focused beams of ultrasonic frequencies aimed at particular areas of the brain, and it turns out it does seem to have an effect. The paper specifically talked about the research that went into using this focused ultrasound

on the so much somata sensory cortex. So essentially they the area where we have our our our senses, you know that that part of our brain. That's that's uh. Particularly, they were targeting tactile uh census, so our sense of touch. So here's what was going on in the actual research. They focused beams of sound waves at five killer hurts, so well above that twenty killer hurts range of human hearing and for the record, well above the hearing range

of basically any animal. Yeah. Uh, So they targeted this through the skull at that cortex, and they saw that there did seem to be some effect of the quote modulation of the firing of neurons end quote. So how how was that a thing? This is where science looks at us and just goes there's an effect, but the actual mechanism of the effect is not understood at this time. There are some hypotheses about what's going on. But there's not you know, there's not a oh it does this

because of this? So what are some of those hypotheses. This is the one that was in the paper, which I love. So it says the pulse acoustic pressure wave may locally shift the balance of excitation and inhibition by acting on mechanically sensitive components of the brain, including cell membranes, ion channels, and synaptic vesicle cycles. So, in other words, if I can paraphrase, it's affecting the modulation of neuronal

activity by poking stuff with sound. So it sounded like to me the method of poking your brain without cutting your skull open, right right, It's that same pushing effect that we were talking about with the cancer cells, right yeah. So so it's just just really localized. I like to think of it as like, because I'm from the Deep South, I like to think of it as a bunch of guys just standing around with a little sound emitter saying, hey,

y'all watch this. Now. Clearly that is not what happened, But I thought you were going to say it's like a bunch of guys standing around a possum and a ditch poking it with the stick. Well, you know, we're my my my chart of the evolution of man kind of resembles what you're talking about right there. It's we don't know that. These scientists involved didn't sit there going like, hey guys, so now we can say allegedly because we're alleged, No, no,

we're not. But potentially this could mean, let's all right, the mechanisms aside, we don't understand the mechanisms fully yet or really we just had some vague ideas of what's going on. But that aside, ultrasonic stimulation might be able to offer neuroscientists a more precise tool for neuronal stimulation,

in other words, using magnets, using electricity. It can be you know, you're you're kind of aiming in the general direction of the area you wish to affect, knowing that you're also probably going to affect some surrounding areas, right That might have consequences, and it may have it may end up affecting the outcome of your research without you being able to, you know, use a full level of confidence about what's actually happening. This would allow perhaps a

greater level of precision. Uh still not you know, pinpoint precision. We're talking about the area that would be about the size of the tip of your little fingers. So not like you couldn't target specifics neurons, you could target clusters. UH. But it also could be h method of safely testing this because again we don't have to worry about causing

tissue damage uh. And the research itself, they looked at how this actually did allow the people undergoing the tests to have a better ability to detect subtle differences in tactile sensations. So imagine that you have two different things that come into contact with your skin, and perhaps the difference between the two are there there. You know, from from a tactile sensation standpoint, they are not that different

from one another. They discovered that using this ultrasonic stimulation, people who the people who did have that we're better able to tell the differences between the different tactiles stimulations than was who did not. So they had an increased facility from their sense of touch, which means that you might be able to through this modulation do lots of different things, including you could potentially address various disorders, could

be part of physical therapy YEP. It might even eventually become something similar to what we've seen with the transcranial stimulation, like the direct current stimulation. The idea of being able to boost things like a learning ability that, of course is so far off into the future though, that's way trickier than than touch. Yeah, we're we're we're talking about there's potential, but that potential may never be realized. Yeah. I wouldn't describe it in terms of time. I don't

know IF's necessarily so far off. I describe it in terms of uncertainty, like we don't really know, I mean, far off from a sense of what we are capable of knowing right now, as opposed to I mean it may turn out like sometimes science comes up with things where we don't fully understand the way it's working, but we have a practical effect, so we go with it.

Sometimes that turns out. That'd be great. I feel I should just have like a song version of twenty to forty years that I just like to play a little, a little jingle, yeah and now forty years by Noel Brown. This is the point in our notes where we had decided that we were going to split the episode and pick up again in another episode, because we just got so much to talk about with sound, and obviously, you know, we had to lay the groundwork and ultrasonic frequencies was

that was a great way to get started. And in fact, we'll pick up with a different application of ultrasonic frequencies that has nothing to do with the field of medicine. Ah. Yeah, we're over talking about the gross spot stuff that we have been talking about all episod. Yeah, so we're gonna have some non gross, non body stuff and maybe some gross stuff that has nothing to do with bodies in

our next episode. You'll have to tune in and find out. Meanwhile, if you have any suggestions for future episodes, uh, you should definitely get in touch with us. Let's know what you think. The email address you can send that to is f W Thinking at health stuff Works dot com. Or you can drop us a line on Twitter or Google Plus or Facebook. At Twitter and Google Plus, we are f W Thinking, search FW Thinking and Facebook. It'll

pop right up. You can leave us a message. We've been getting some great requests and some notes from you guys that we really do love. We read all of them, So keep an ear out because we're going to have some listener request episodes coming up very soon, and yours could be the next one. Just send us that message and we will talk to you again about sound really soon. For more on this stuffic in the future of technology, visit forward Thinking dot Com, brought to you by Toyota. Let's Go Places,