Sound (featuring audio wizard Mat Keselman)

23:20leaves me wanting and I feel like there's something missing and then there's conflicting things in different popular science publications. And then I found you guys and you break it down and that was really enjoyable. And then I thought, why don't I just tell them that I can make them sound even better? Yeah, we got an email out of the blue from you saying, hey, I have notes on your audio engineering. And we dug into it with you. And then eventually we were like, hey, why'd you come make the show better? And we haven't looked back yet. That's right. And so one of the reasons we're super excited to have you on the show is because after Daniel and I do a listener questions episode, we always send the raw audio file exported from Riverside out to the listeners so that they have plenty of time to listen to our conversation and send us an audio file responding.

24:10And almost every single one of them is like, wow, this sounds awful. Your audio guy must do so much work. And so we thought that it would be great to have you on the show to like pull back the curtain and talk about like when Kelly forgets to turn off her air conditioner. How do you remove that sound? And like all of the work that you have to do to make us sound good. Where does that start? Okay, well, first of all, I want to point out that there are different kinds of podcasts that have different needs, right? Everybody's familiar with the comedians just talking with no editing, with no nothing, and they leave all the mistakes in, and that's part of the charm.

24:52There are also narrative podcasts that tell a story kind of like a movie, and our very own network has a few examples of that, like Red Elvis and the Buzz Aldrin show. I don't know if you've heard that one. But then there's also the informative kind where you're basically enjoying a lecture. And I feel like this is kind of like a lecture mixed in with some lighthearted comedy. And the thing about lectures is that they take a lot of time to prepare. And you two do something that very few people can do. And that is that you basically deliver two lectures a week, often on topics that you're not specialized in.

25:31And it's no surprise that sometimes you need to write on the fly. I mean, otherwise, it's just not possible for any person to deliver that much information without having to stop and sort of rewind and think back on it. And I think we all sort of treat it that way where you have your outline and you have your idea. And sometimes you come up with a new idea while we record. and then you try it out a few times until you get it right. And then you send it off and you hope that I put it together. I feel like you really, you get me, Matt. You get me. And I want to start describing the podcast now as lectures with light comedy because I feel like that's actually, that's a pretty good description.

26:13That's really what it is, right? It's like weird things that are very hard to understand sometimes broken down into small bite-sized understandable pieces with some prolapse jokes.

26:27Which is my favorite type of entertainment. We need constant goat updates, you know? People are curious. Well, she's kept her outsides on the inside recently, so that's nice. Wonderful. Yeah. Well, from my perspective, I lean heavily into this editing because I know that we can go back and fix something or say something a better way. I speak differently than I do in person or if I'm lecturing to a class. I'm lecturing to a class, I don't often back up and say things another way, just go with it. So I think the listeners are hearing a very unusual slice of our speaking, you know, the intended for editing, but unedited version, which is not how like we have a conversation normally.

27:07Right. And if listeners want some inside baseball, I always send you the finished episode or a draft of the episode. And then you listen intently and go, oh, actually that detail is technically right, but there's a better way to say it. And then you send me a pickup. because you're perfectionist and you want everything to be correct and true. And that's very admirable as well. And you're always a really good sport when we're like, oh, actually, thank you so much for editing all of that, but I'd like to do it again. So let's make this concrete. Can you show us some examples of what you get and then what you send us back?

27:40Show us the raw, unedited Daniel and Kelly craziness and then the smooth matte output. Sure. I have two separate kinds of examples. Here's a couple where the noise reduction was already done. And we're going to focus on your writing on the fly, if you will. So take a close listen to, we'll start with Kelly. Uh-oh. Trying to communicate this idea. Backing up a couple of times, a couple of uhs and ums. And then after we'll listen to the cut up version. And I have no idea what file Matt picked. So I'm on the edge of my seat. And we don't really have a good framework yet for predicting. Like if you took, you know, X and say you decided you were going to take.

28:27What's a say you were going to take lions and domesticate them. OK, so there's that. Here's here's the edited version. Yeah, right. And we don't really have a good framework yet for predicting. Like, say you were going to take lions and domesticate them. I'm being ridiculous. Right. But like, say you decide. That's not ridiculous. That sounds awesome. I would love to have a house lion. Hey, whatever happened to the house lion I requested anyway? I need a few more years. Yeah. So, I mean, you can see that you got this idea of comparing it to lions and it came on the fly. So you just needed to work through it, which is great because I think everybody would rather hear what you intend for them to hear and not for you to sort of back away and just say something that's easier to say.

29:16And I think that these on-the-fly moments are what make our conversations really fun because it is a conversation. You're thinking on the fly. You're coming up with new ideas. You're responding to questions. Also, we could never pull off a scripted podcast twice a week. That's just so much more work. And on top of that, I'm a terrible actor. So if I had to read a scripted podcast, it would sound really stilted. The only way for this to work is for it to be a natural conversation. I massively appreciate that. I can stumble and start over many, many, many times and know Matt is going to listen to all of that and pick out the bits that make sense.

29:50And you're amazing. Thank you. Sometimes you do put a lot of faith in me. And just to be clear, what I mean by that is that you'll have a great first half of an idea. And then you might ride on the fly and work out the second half of the idea. and then when I put them together, sometimes they could sound a little bit disjointed. Kind of like a milder version of this real segment that really aired on TV.

30:24I don't want your recordings to sound like that, even though it's completely normal for speech cadence to change over time. But when you put it all together and remove the gaps in the middle, it becomes more noticeable. So sometimes I have to do things like tune your voice on certain words or look around and find other times when you said that word in the episode or in other episodes and use it to help build one cohesive sentence. And just to be clear, I never change what you've said. I might just change how it sounds, but the ideas are purely yours. How often do we do that to you? I'm feeling really bad right now.

31:02It's not something you do to me, but it probably happens more often than you think. Oh, no. Oh, no. Which is completely normal. You're focused on educating the masses. I'm focused on making it sound smooth without anybody noticing anything was done at all. Well, thank you for making it sound so good and making it sound like you haven't done anything. That's the most flattering part. You want to hear one of you, Daniel? Yes and no. I do. I do. All right. Let's do it. Okay. Here we go. The before and after for Daniel. Had that one piece of data argue that the earth could be a flat disk that was perfectly aligned to make a circular shadow.

31:39Yes. Ooh, boy. That was rough. For some reason, like, were you at a supermarket? Because you hear that beep in the, listen again? Had that one piece of data argue that the earth could be a flat... Did you hear that beep? Where was that? Yeah, I was not buying a can of olives or something at the same time as recording the podcast. I have no idea where that comes from. So here's the after. We had that one piece of data argue that the earth could be a flat disk that was perfectly aligned to make a circular shadow. Yes. I sound great afterwards. Thank you. Yeah. And again, like you said, you don't talk like that in person.

32:20It's just that you're trying to communicate things that are new to you in some way and in a way that fits for broadcast. Okay, so when I listen to the audio files after I send them to you, I'm like, oh, shoot, I left my air conditioner on or Daniel was trying to explain general relativity at the grocery store. Like, how do you remove like the beeps and the background noises? Like, how hard is that? So there are many different types of noises and many different solutions. Some are automated, some are not. So if it's here, I have some examples. Oh, good. Here is some unprocessed. Daniel, let me know if you can hear that background noise.

33:01So Bell's paradox involves length contraction, the fact that when things move fast, they look short. So relativity tells us two things. Moving clocks run slow and moving objects look short. So that kind of noise is probably the easiest because it's consistent. It sounds like I'm crinkling paper or something. That's a different thing. That's mouth clicks. And that's a normal thing that happens when you put a microphone really close to the human mouth. It's weird how it doesn't happen in person, but it does on mic. For that kind of noise, it's because it's consistent. We have software that we basically tell the software, look at this, as long as there's no talking, look at this piece of noise, identify it as noise.

33:43And from now on, remove anytime you encounter that. and they become more and more sophisticated over the years to the point where they're quite transparent at it. It's still, in many cases, if you go too hard, things start to sound watery and sort of weird. So you have to be careful with that. But dig into that a little bit more in detail, because what you're saying is it's consistent. So you can measure it when the person's not speaking and then you have a template to remove it, but still it's varying. So is an average removal, It's a statistical removal because it can't remove the exact noise moment to moment because there is variation.

34:18We heard it. There is variation, but it's fairly predictable. Like an air conditioner, unless the air conditioner is changing temperatures, is going to give or take make the same droney noise throughout the recording. But yes, sometimes I do catch that throughout the recording, sometimes the air conditioner changed gears and then it's no longer being recognized. And I have to compensate for that. there are settings where it's supposed to follow the noise itself. I don't find those to be very good yet, but tech changes all the time. Maybe tomorrow there'll be a good one. And is this noise removable because it's at a different frequency than the voice?

34:58So you can identify it when I'm not speaking, and then you know exactly how to remove it, and you can remove it without removing the voice? Or does it overlap with the voice, and so you are affecting the actual voice as well? Oh, okay. That's a great question. You really want to look under the hood. So the way it really works is that the recording is divided into smaller bands of frequencies, and each frequency is given what's called a gate or an expander, where if a lot of volume hits that area, it's allowed to pass through. So speech, for example. But if there's a quieter moment, it enhances the quiet moment and makes it even quieter.

35:37So if you really listen closely, you may be able to notice that there are moments of noise when you talk. But because you're talking and the noise is only present as you're talking, it's not perceptible. A lot of this is about magic tricks and not actually about doing what you think we're doing. By magic tricks, you mean distracting people and understanding how attention works? Yeah, I mean real magic, not magic magic. Where sleight of hand and stuff like that. I love that you call that real magic. That's awesome. Okay, so then how would you remove something like the grocery store? I was not at a grocery store.

36:16I want that on the record. I think you were. I saw it. I saw it. So for a noise like that, or like goats, Kelly. oh no you can hear my goats oh yeah they're goats really they're goats yeah oh i'm so sorry oh no it's totally it's not your fault that they're goats they do goatey things uh for things like that for for noises that are not consistent or predictable oh which by the way let me back up one second noise canceling headphones work on the same principle so noise canceling headphones can cancel predictable noise once they recognize that noise. However, if somebody's talking to you or there's a dog barking, you may notice that your noise-canceling headphones don't work for this very same reason.

37:00So if there is a dog barking or a goat, luckily we live at a time where I can just open it up in a spectral graph and I can actually see all the sound. It looks like splotches. And I can see the goat bleed to an extent and I can draw it out like in Photoshop. Whoa, that's amazing. And so what you're looking at is the amplitude versus frequency? Yeah. Time is the X. Frequency is the Y axis. And then amplitude is color. Oh. Oh. Fascinating. Bright orange means it's very loud. So I can actually see all the harmonics of the goat or a door being slammed or a plane flying by. And sometimes it's hard to draw them out because there's other stuff happening there.

37:41But in most cases, it just takes time. You have to stop, capture that piece, and follow the goat and remove it. How does Daniel's voice show up different than mine? So Daniel has a very deep voice. What does his look like relative to mine? Well, too bad this is not a visual show. So what you would see for any human is just a series of lines on top of each other. Most sounds, really. And the lowest line is the actual note that Daniel or Kelly are saying. And then all the lines, the notes above that are harmonics that we don't perceive as individual notes, but they're the sort of fingerprint that make Daniel and Kelly sound different.

38:24Even if you sing the same note, for example, it's just a different combination of those harmonics. Huh. Like for the same reason that like a guitar and a violin sound different when they're playing the same note, because there's a range of frequencies that gives you the mental fingerprint to identify it. Exactly. That's all it is. All right. Well, let's take a break. And when we get back, we're going to chat with Matt about how software is making his life easier or maybe not. And whether or not he's actually an AI.

39:00I'm Manga Shatikular and I'm back with a new season of the podcast Skyline Drive. This time I'm diving into a rabbit hole of peptides, organoids, blood boys, blue zones, and brain replacement to try to understand what this longevity obsession is all about and what it really means to live forever for all of us. I learned about some rad science. I can make a brain for you and then we can test what draw is the best. for your brain, as opposed to his brain. Here's some hard truths. I would expect Indians to age faster, but I did not expect it to be almost a four to five year acceleration. And get myself into a world of trouble.

39:45I'd say probably start bone smashing. That doesn't work. Make it look more defined. They say it works. I don't know. Listen to Skyline Drive, How to Live Forever on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. I'm Jake Brennan, and on my podcast, Hollywoodland, I revisit some of the biggest stories from Hollywood history, separating the myths people want to believe from the reality underneath them. Like how the story of Marilyn Monroe isn't just the story of a Hollywood icon. Marilyn Monroe has become so iconic that her death can only be explained through conspiracy theories.

40:25And for some fans who can't let go, these stories have metastasized from conjecture to accepted fact. So on August 4th, 1962, Marilyn Monroe died. Then the rumors started and she died again. And now we're going to set the record straight and learn about the way Marilyn Monroe actually died the third way. Learn more about what happens when fame, media obsession and conspiracy collide. Listen to Hollywoodland on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

41:23that carried them to their highs. Listen to Unshaken with Gary Vee on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. In 2015, teenager Joy Morgan discovered strangely compelling YouTube sermons from the religious group Israel United in Christ, or IUIC. Her initial curiosity developed into devotion. She distanced herself from friends and family, embraced new identity, immersed herself in the IUIC and believed she'd found the truth. IUIC is the best family that I've ever had. In fact, she had found what many called a cult. And on Boxing Day 2018, Joy disappeared forever.

42:05In the new six-part investigative podcast, The Missing Sister, Charlie Brinkhurst Cuff and Free Turn explore Joy's story, the family she left, and the religious group she found. You know when you get that freedom, you just, I don't want to be here. I want to get out. I want to go here now. It's a story about truth, lies, a young woman yearning to belong, and a family still waiting for answers. All episodes available now to binge. Listen to The Missing Sister on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

42:45And we're back, and we've got Matt in the hot seat today. We are quizzing him about how he makes us sound not horrible because we sound pretty bad in the raw audio that we send to Matt. So AI is like everywhere now. So could you like tell AI, hey, here is an interview from two people. For starters, cut out every time they say um and remove all the background noise. Like, are we there where that could happen? Or yeah, where are we with AI now? We're not there. We might be there. I have no idea what's going to happen. Maybe next month, none of us will have jobs. I know that some people have very strong beliefs about what's going to happen.

43:24I think nobody knows and we may hit a wall or it may never stop. See, the thing is there are tools that can do things like that, but then they require adult supervision where you check what it did and then you find that it deleted a very important question or, you know, things like that. So it doesn't help me. It's still faster for me to do it all myself because I work pretty fast and I don't have to go back and try to find what's missing. The tools I use the most with AI are for noise cleanup. That's also another option if I don't draw it out with a pencil tool is there are AIs that are pretty good at being able to tell what noise is and they sort of split into two categories.

44:09One is it removes the noise on its own using all kinds of cool phasing algorithms. And there's one that recognizes your voice and then re-synthesizes your voice completely from scratch. Wow. Wow. Which is a little weird. Scary. Scary. Yeah. Well, I had a listener write to me once that they heard an AI-generated podcast and that one of the hosts on that podcast sounded a lot like me. And I was like, what? So then I listened to it and I was like, that does kind of sound like me. And then I realized there are hundreds of hours of my voice out there for anybody to train an AI to make an AI Daniel.

44:47And you only need five seconds now. And by the way, PSA, I don't know about your bank, but my bank has this voice print identification if you call them. Yeah. I asked them to turn that off. Yeah. Because it's incredibly easy, especially for anyone that, you know, has their voice out there for anybody to fake your voice. So that is no longer safe if you have that enabled at your bank. And I'm not endorsing it, but I did find this AI-generated podcast to be pretty good. And I did a little experiment where I took one of Katrina's latest papers and I ran it through and I had produced a 15-minute podcast about it.

45:20Then I sent it to her and didn't tell her it was AI-generated. I said, hey, I heard this podcast about your latest paper. And she listened to it and she was really excited. And she shared it with her laugh. That is weird. So it was surprisingly good. It's pretty compelling stuff, unfortunately. Well, so I think you should be flattered that out of all the voices they could have picked, they decided to scrape your voice, Daniel. It's a good voice. I don't know that they did. You know, just generic podcast dude with a deep voice, I guess. But no AIs out there making goat jokes, Kelly. So you're unique.

45:54Yes. Oh, that's great. I'm so glad. So Matt, even with the help of software, we send you about an hour, an hour or 20 minutes of audio. It gets compressed to about an hour of podcast. How many hours go into editing? Anywhere from five to 10. Wow. Depending on the subject matter. Yes, yes. Well, look, if it's about particle accelerators, Daniel already has all that stuff memorized and it's easy to do. Or if we're talking about keelie fish or something like that. but if somebody throws you a curveball question that you had to look up then it could take a bit longer if there's a guest it usually takes longer because you have a rapport and a banter that you're used to and then if somebody else comes in they may not have that same vibe and it takes a bit of time and I want to point out that five to ten hours may sound like a lot but it's not a lot or unusual at all if you think about it it's usually roughly about an hour and half of raw audio that I get, I have to listen to it at least one time.

47:03So that's already an hour and a half. Then I need to do some noise reduction, which can take, you know, 30 to 50 minutes, depending on the type of noise there is. And then from there, every edit that I make, I have to first hear it, stop, listen to it one more time to make sure there is a problem, do the edit, which takes between a few seconds and a few minutes, depending on the edit, and then listen back. And these little things all add up and before you know it you're easily crossing the five hour mark by the way one other thing that i forgot to mention is there's the editing sort of to help everything feel smooth and make sense but then there's also the issue of comedic timing yeah over web conferencing there's a delay whether you like it or not and it's not something as easy as shifting one voice back because kelly would say something funny daniel would accidentally talk over Kelly because he's been waiting because there's a delay then realized that was funny laugh at that Kelly also hears a delay so she's already trying to damage control Daniel not laughing and it becomes this mess where I'm like there's a very funny joke here and both laughed at the joke but because of that delay it sounds a little bit train wreckish so that's another thing that I go Wow, what a review.

48:26Well, because I know that in person, you both would have this banter and laugh and it would be so I'm sort of time traveling in a way to put you where you wanted to be, at least where I perceive you wanted to be. So that's also a part of it. Thank you for that. Thank you for making us funny. No, you're the funny ones. I just undo the damage the Internet causes. So why does my voice sound so much better in my head? So like when I listen to the file you send me, I think, wow, this sounds way better than when I actually was like talking to Daniel. In this version, Daniel laughed at my joke right away.

49:02But I still I still cringe because I don't love the sound of my voice when I hear it back to me. But when I'm saying it, it doesn't sound so bad. So why why is there that disconnect? I think you have a great voice, Kelly. I love hearing it. Thanks, Daniel. Agreed. Great voice. Thanks, guys. Otherwise, people wouldn't be listening as interesting as you are. If you had bad voices, people would move on. It's a matter of perspective. So we hear everything else and everyone else through our ear canals, right? There's air outside and that air vibrates and it goes into our ear canals and we hear it. for ourselves, a big chunk of our voice travels through conduction into our ear from the inside.

49:42And that's what people call the inner ear. There's no actual inner ear. I used to think there was when I was a kid, like a third ear in your throat. There isn't one. You're basically hearing sort of a muffled version of yourself because it's traveling through soft tissue and bone. And then you're also hearing a little bit of yourself through the air going back into your ears. So it's a different sort of like i don't know when i look in the mirror i'm gorgeous when i look at a photo i look like a crescent moon i noticed that my face is curved and i never noticed that in in the mirror because it's just a perspective i'm not used to and i think that's exactly what happens with your voices you're used to hearing it a certain way and no matter how the recording sounds you'll think it sounds worse because you're just not used to it so if somebody was to put their cheek up against Kelly while she was speaking so that her voice traveled through their soft tissue?

50:33Would they hear Kelly's internal version of her voice? If you were somehow able to model Kelly's innards from her throat all the way up to the top of her skull and put that between the other person, yes, it would be very strange, but yes. I'd just like to put on record that when I see you, I never think crescent moon. But I will now. I have to tell myself the same thing is that that tiny lack of symmetry, which every human has, is just accentuated because I never see it from that angle. Right. You know, and I feel like most people, when they look at a photo compared to the mirror, they're like, oh, what is that?

51:12What happened? Yeah. So you mentioned earlier about real magic and how a big part of this is knowing how it's going to be received by people. Tell us more about that, about how understanding the way sound is actually perceived and the way people pay attention changes how you do your editing. And tell us about psychoacoustics. So, Daniel, you're going to be proud of me. Before I even knew who you were, I've talked to my students about aliens a lot. Plus 10 points. We were all meant to be together. Yeah. The reason I do that is I always in the first class, I tell them this is a class for human beings in Earth's atmosphere.

51:53Right. Because first of all, sound behaves differently through different materials. And second, humans have evolved to process their senses in ways that are useful to them. Which is another way of saying that what we hear and see and feel is not reality, but our useful version of reality. and sound is no exception to that. I think we may not realize how much of a role it plays. My theory is because there are no ear lids. Go on. With sight, you have these eyelids where you can close them and not see and get an idea of what it's like to not have that sense. You also have to directly look at the thing that you're looking at to perceive it.

52:38And with sound, you hear everything around you. You don't have to look at it with your ear and you've never closed your ears, right? Your ear balls are always exposed. So it's a sense that's so enveloping and so much part of our lives that we sort of take it for granted and not understand how much information we're constantly getting from our surroundings through sound. And we don't even have the language for it, right? You have to adapt the language from eyes. Like you said, look at it with your ear instead of hear at it with your ear, because that makes no sense, right? Yeah, so we think there's just this baseline of nothing, but in reality, you know the size of the room you're in and what the walls are made out of before you look and tap on the walls.

53:22You know from how sound reflects in that room. I have a question about that because I've been told many times to record in a room that doesn't have auditory reflections, right? like surround yourself with laundry or something. Right. Because nobody wants to hear the room that you're in. So isn't that weird for people to hear audio that sounds sort of like disembodied or derumified? No, because it's far from disembodied and derumified. Unless you've been to an anechoic chamber, you have never heard silence in your life. It's a very... Have you been to one? No. I highly recommend it. It's weird.

53:56Sounds like a torture device. You know what? People say that. There's a rumor that no one has ever lasted more than 45 minutes. Not true. I've been there for hours. But you can hear blood rushing through your ears. Wow. You can hear everything. And not only that, if you're there with a buddy and they turn around and talk and speak the other way, you can barely hear them. We don't realize or we take for granted how much of what we hear is actually reflections of the source and not the source itself. So, I mean, an example of some important psychoacoustics that engineers have to keep in mind and also the answer to the listener question.

54:33What do you think? What is the type of sound or sound that humans hear best? I would have guessed that there's something similar to our visual range where there's a whole spectrum of frequencies and we can see something in the middle where in the middle basically means where we can hear, which makes it kind of a non-answer. Right. Well, that's actually a good comparison because with sound, you can see red just as well as you can see blue with sight. But with sound, it doesn't work that way. With sound, we can hear frequencies from 20 vibrations per second, 20 hertz, to 20 ,000 vibrations per second, 20 kilohertz.

55:10But out of those, we don't hear them all equally. The frequency range we hear best is between one and five kilohertz. And that is the range of leaves rustling and twigs breaking. And jaguars creeping up on you. So that predators don't creep up on you. It's also the range of a baby crying. You can hear a baby cry from way farther away than, I don't know, a car engine revving at the same distance, same volume. It's also the sound of a candy bar wrapper, isn't it? That is correct. Yes. Yes, it is. And we've been using that. For example, police sirens are tuned to that frequency range. And that's why you may have found yourself sitting in your car or walking, hearing a siren, looking around, being like, I don't see the police anywhere.

55:54Where are they? It's because we're so good at hearing those frequencies that we can hear them from so far away that we can't even see the source of the sound yet. Wow. So then how does all of this shape your editing? Are you trying to push my voice up to police siren frequencies? well i definitely have to make sure that intelligibility is there and that is in those frequencies but there's a challenge here because we hear those frequencies so well they become annoying very quickly too oh because we're acutely tuned to them so there's a balancing act where if there's not enough it sounds i can show you do you want me to show you yeah yeah Please.

56:34So here, let me play process Daniel here. So Bell's paradox involves length contraction, the fact that when things move fast, they look short. So relativity tells us two things. Moving clocks run slow and moving objects look short. So now I'm going to take out that frequency range that I was just talking about. And you'll notice that you can still hear Daniel. He's loud. But the part that makes him human, loud, I mean, loud is the volume I made him. not because Daniel is a loud person. But the intelligibility is just not there. Take a listen. So Bell's paradox involves length contraction, the fact that when things move fast, they look short.

57:16So relativity tells us two things. Moving clocks run slow and moving objects look short. And now I'll exaggerate those frequencies and you'll see that it'll kind of hurt your ears. So Bell's paradox involves length contraction, the fact that when things move fast, they look short. Right? So I have to find a happy medium. And that is sometimes something that has to be done temporally. So I have to make sure that some words don't have too much of those frequencies and others do. That's just one of many ways in which I have to look at the waveforms and understand the science and then also understand the psychoacoustics, the psychology of how humans perceive this stuff.

57:58Well, you're doing a great job because I sometimes meet listeners in real life and they'll say to me, oh my gosh, it's so weird. You sound just like you do on the podcast. So you are reproducing us faithfully. I did it. So how much physics did you have to learn to be this good at your job? I see what you're saying. Yes, audio engineers are real engineers. We're like the dentists of the audio profession. She's just trying to suss out if you're on the physics camp or the biology camp. She's wondering if you're biased. See, I'm stuck right in the middle between physics and biology. Exactly. It's a good place to be.

58:34Yeah, it's a very fun place to be because who cares about physics if it's not for how it affects sentient beings? Amen. Amen. I have thoughts about that. I'm so glad we got you on. You know, Matt, you should be on the show every week. I see. Kelly just wants to invite people on the show who will disagree with me and gang up on me. So let me tell you another psychoacoustic phenomenon called masking. The way this works, and this probably, we can't ask evolution, right? But it looks like we've developed this property to curb overstimulation. What happens is if there are certain, and it's very predictable, if there are certain frequencies present, we are deaf to certain other frequencies in those moments.

59:23It's just like a blind spot in the car. Like no matter what mirror you look at, you will not see the car right next to you if they're in your blind spot. So we have these blind spots that are constantly very quickly changing as different sounds are present. And very smart programmers mapped out the exact way we have these blind spots and figured out, you know what, we can save a lot of space in audio files if we just throw that stuff away. Oh, wow. And that is how the MP3 file format was born. It does throw away a lot of things, but it throws away only things you would not perceive anyway. And so if you've ever had this debate or just heard someone claim that MP3s just don't sound like waves, man.

1:00:08There's just something missing. Not necessarily. If it was a well-encoded MP3, you will never hear what is missing. Wow. Because you're human. our imperfect hearing has really helped us save on file sizes. However, if an alien came and you went, here's a WAV file, like here's the recording, and then here's my MP3 of that recording, to that alien, it might sound completely different and upsetting because they don't have our same perception. Those aliens who listen to the podcast might be really sensitive to those frequencies that our audience, our human audience can't hear. As far as we know, when we listen to an MP3, our pets are suffering.

1:00:49they don't seem to be complaining but they're definitely not hearing what we hear when we listen to the original recording the way that humans do so this is like the moral equivalent of masking out the ultraviolet off of a painting and a bee might see the painting very very differently whereas a human would be totally unaware kind of it's like if humans when you see yellow you're temporarily blind to purple weird why why why does that happen I don't know. I haven't asked God yet, but I think probably because of the overstimulation thing. I think if we were to hear everything all at once, our brains would explode.

1:01:29I think it's just too much information. So people who get overstimulated, do they hear some of that or is that just a different thing? You know, that's a great question. I don't, that might be part of it. That might be part of it, that they don't experience masking the same way. But the interesting is that it's very predictable, this masking and how it happens. It's very specific. And it's the same for children and for women and for men and for everybody. I don't know that there's a group of people to whom MP3s don't sound right, objectively, like a blind test. So, yeah, I don't know. Maybe some people do experience less masking.

1:02:08Maybe that's part of it. So, Matt, I imagine you have loads of fun stories, in part because, like, Daniel and I always hit record. And then we're like, we totally forgot we hit record. And we have conversations about the most personal things happening in our lives. And then we send it to you. And so you, it's a very asymmetrical relationship. I think you know a lot about the things that are going wrong in my life. I don't know nearly as much about what's going on in your life. I can make you a list if you want to even the playing field. I mean, lay it on me. But so I imagine that one, you know a lot of secrets from people.

1:02:41uh but and tell us some weird funny stories from from life as an audio engineer uh there are many inappropriate stories uh there is okay here's one that is right in the middle between science and and uh some biology and perception so mostly physics so i was in uh santa monica which is uh is it a part of la or is it outside of la boy daniel you're from california you should know this. I don't know. Well, you know, there's the effective LA, which is a big blob of urbanized area. Then there's LA County, then there's LA City. And I don't know the distinctions between all of them. Yeah. I don't understand how that's a municipality because when I was working there, they were shuttling us around from location to location and the names of the neighborhoods and how things fit into the municipalities didn't make any sense.

1:03:32Anyway, I was in Santa Monica filming with Smokey Robinson. Wow. For a very interesting documentary, by the way, called Paid in Full on the BBC and CBC, wherever you are, about the unfair treatment of black musicians throughout history. In any case, I was there with Smokey Robinson and they rented a special villa just for him, you know, the VIP treatment. And there's always this air of When a really important person comes in, no one stops the recording for any reason, right? Do your job. Be quiet. We have a very limited amount of time with this person. So I'm sitting there. I'm set up. I have my computer open.

1:04:18I've mic'd him up. I have a mic on him. I have a mic above him. And I have a spectrum analyzer open just because I didn't really need it. But it shows you all the frequencies in real time. and suddenly during the interview i see these sort of spikes at like five hertz which is way lower than what humans can hear and i'm realizing that even though the microphone is suspended and supposed to not pick anything up through the floor i've created a seismometer by accident and i can see that there's an earthquake coming wow and so in the middle of this interview i go hey excuse me and the director looks at me like what are you doing and I'm like I'm very very sorry I think there's an earthquake coming and we should get ready to evacuate or move away from the walls or get to the I don't remember what you're supposed to do but we're in California I expected everyone to know except for me and they're like what are you talking about there's nothing happening you've this is Smokey Robinson what are you doing I mean, everybody was nice.

1:05:24We're all friends. But as that's happening, the lights start to shake. Oh, wow. Wow. And there's a rumble. And luckily, it wasn't a big earthquake or anything. Everything was fine. But I predicted an earthquake using a microphone and a computer screen. That's amazing. And I interrupted an important recording. And that's magic, right? And Smokey Robinson is now like Matt Kesselman is magic. Everybody knows now. He was like, that's okay, baby. He's got a very, very soft voice. I love him. Well, that is a great story. I don't have any comparable stories of warning famous people about impending natural disasters.

1:05:58It's a very niche story market. All right. Well, thank you for coming on the show and for telling us all about what happens in the background to make us sound so good. Before you go, tell people where they can find out more about you and what you're up to. You can find me for everything at mattkesselman.com. That's M-A-T-K-E-S-E-L-M-A-N.com. And if you don't like to spell things that are complicated, I just bought thegoshfather.com. And that goes to my website too. So you can use that instead. Matt, I appreciate you so much for so many reasons. And now I appreciate that you came on the show. You're the best.

1:06:40There are lots of reasons why the show sounds good and is fun to listen to and easy to listen to. And many of those are because of Matt. Thank you very much. Amen. Thank you for having me. This was a lot of fun.

1:07:18Come engage with us. You can email us at questions at danielandkelly.org. We really do want to hear from you. And you can find our website, www.danielandkelly.org, where you'll also find an invitation to join our Discord, where everybody comes and talks about the amazing universe. And we also have the most amazing moderators. This is an iHeart Podcast. Thanks for joining us. I'm Mange Shatikular and I'm back with a new season of my podcast Skyline Drive This time I talk to scientists, biopunks, curmudgeons, blues owners, super seniors and Goa's top cryotherapy lab to try to understand this obsession with living forever and what it means for all of us And I get into a bit of trouble along the way I'd say probably start bone smashing That doesn't work Make it look more defined They say it works, I don't know Listen to Skyline Drive, How to Live Forever on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

1:08:17Why do some women yearn for Shakira's black hair to make a comeback? And whatever happened to the power couple of my dreams, Mariah Carey and Luis Miguel? I'm Maria Garcia. You may remember me from my podcast, Anything for Selena, or My Divo. And now I'm back to unpack more stories from the present and the past. Listen to Muy Excited with Maria Garcia on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

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