WEBVTT - THE HUMAN SCREAM 0:00:01.480 --> 0:00:04.960 Welcome to stuff you should know, a production of iHeartRadio. 0:00:11.080 --> 0:00:13.440 Hey, and welcome to the podcast. I'm Josh and there's 0:00:13.560 --> 0:00:15.760 Chuck and I'm not going to scream to start this 0:00:15.880 --> 0:00:18.040 off because I care about all of you listening. 0:00:18.760 --> 0:00:24.320 Yeah, that was a new for you. Yeah, we're talking about. 0:00:24.520 --> 0:00:27.760 Julia helped us out with this one, and I commissioned 0:00:27.760 --> 0:00:30.800 this one. And I don't remember what instigated it. It 0:00:30.800 --> 0:00:35.720 definitely wasn't from hearing somebody scream. I may have seen 0:00:36.280 --> 0:00:39.199 an article or something that piqued my interest and I 0:00:39.240 --> 0:00:42.239 was like, wait a minute, what like screaming? Is interesting 0:00:42.320 --> 0:00:45.160 that people scream and for all different kinds of reasons 0:00:45.680 --> 0:00:50.919 people scream, and that's why I picked it. 0:00:51.040 --> 0:00:54.840 Here we are. Yeah, I was very surprised and impressed this. 0:00:54.840 --> 0:00:57.960 It's one of those ones where you just think you 0:00:58.000 --> 0:00:59.960 know about it because you never really thought about it. 0:01:00.120 --> 0:01:02.240 When you diving into it. There's a lot more to 0:01:02.360 --> 0:01:05.280 it than you ever realized. Although all of it makes 0:01:05.280 --> 0:01:08.560 sense anecdotally, you're like, oh, yeah, oh yeah, I've done that. 0:01:08.920 --> 0:01:12.080 I've screamed like that. I'd screamed and screamed and screamed 0:01:12.080 --> 0:01:15.600 again it. Yeah, I like ones like this. I guess 0:01:15.760 --> 0:01:21.880 human human nature explained, and there's a comment there somewhere. 0:01:21.480 --> 0:01:24.720 Somewhere in there definitely not a colon. We should get 0:01:24.720 --> 0:01:26.440 some nuts and bolts out of the way. As far 0:01:26.480 --> 0:01:29.320 as like, everyone knows what a scream is. It's obviously 0:01:29.360 --> 0:01:32.240 a very loud, high pitched, harsh thing on the ears. 0:01:33.080 --> 0:01:35.840 It's a sound that you make with I was about say, 0:01:36.080 --> 0:01:38.000 with your mouth, but we'll get to the parts that 0:01:38.040 --> 0:01:41.560 make the scream. But nuts and bolts wise, the scream 0:01:41.640 --> 0:01:43.640 is in about the eighty to one hundred and twenty 0:01:43.640 --> 0:01:51.720 decibel range. In volume, sixty decibels is normal speech unless 0:01:51.720 --> 0:01:54.520 you're my wife. That's more like an A seventy five. 0:01:54.600 --> 0:01:59.320 I would say she and her her friend Stacy, or 0:01:59.320 --> 0:02:02.560 to the loudest humans on earth, and they admit that 0:02:04.000 --> 0:02:07.240 they're not wallflowers, and they own it and I respect it. 0:02:07.400 --> 0:02:12.679 Nice they reach frequent Not Stacey and Emily, but humans. 0:02:13.520 --> 0:02:16.000 I'm sorry. The human scream can reach a frequency in 0:02:16.000 --> 0:02:18.960 the range of two thousand to three thousand herts, whereas 0:02:19.000 --> 0:02:21.760 a normal talker is about eighty to three hundred herts. 0:02:22.240 --> 0:02:25.160 Yeah, and for dumb dums with sound like me, the 0:02:25.240 --> 0:02:28.000 higher the hurts, the higher the pitch, so hurts is 0:02:28.000 --> 0:02:32.320 a measure of actual frequency. Pitch is basically a measure, 0:02:33.000 --> 0:02:36.760 a description of how we experience that frequency. 0:02:37.520 --> 0:02:40.000 That's right, And just to clear up something for what's 0:02:40.000 --> 0:02:46.040 coming later. A sound, a tone can have two different frequencies. 0:02:46.160 --> 0:02:47.520 I've got it. I have it now. 0:02:48.520 --> 0:02:50.359 Okay, that's it. 0:02:51.520 --> 0:02:53.840 No, I can't wait to explain it later because it's 0:02:53.919 --> 0:02:55.920 gonna get flubbed all over the place. 0:02:57.000 --> 0:03:01.760 Well, it isn't intuitive like you would think, like a 0:03:01.800 --> 0:03:06.680 guitar string makes like, you know, one frequency range. But 0:03:06.800 --> 0:03:08.960 it's just yeah, it's not true. It's one of those things. 0:03:09.240 --> 0:03:11.360 Yeah, this is not true. We'll just leave it at that. 0:03:11.480 --> 0:03:13.440 But we're getting ahead of ourselves, chuck. 0:03:13.960 --> 0:03:15.320 Yeah. Back to screaming, right. 0:03:15.360 --> 0:03:18.400 Yeah, because if you think about screaming, I always think 0:03:18.440 --> 0:03:21.560 of someone screaming, usually in a horror movie or something 0:03:21.639 --> 0:03:24.440 like that. I haven't heard too many, like real deal 0:03:24.480 --> 0:03:28.880 screams in real life, which is nice. But we're not 0:03:29.000 --> 0:03:31.920 the only animals that scream. There's plenty of other animals 0:03:32.000 --> 0:03:35.560 in the animal kingdom that scream that we know of. 0:03:35.800 --> 0:03:38.080 I'm quite sure there's plants that scream too, we just 0:03:38.080 --> 0:03:45.600 can't hear them. Maybe but birds scream, seals, marmots, mountain lions, 0:03:46.120 --> 0:03:49.080 and I didn't know giraffes scream. That's got to be 0:03:49.120 --> 0:03:54.720 off putting. The funniest scream of all as a goat screaming. Yeah, 0:03:54.920 --> 0:03:59.400 if you have never witnessed a goat scream, go right 0:03:59.440 --> 0:04:02.680 now to YouTube and just look up goat screaming videos. 0:04:03.120 --> 0:04:05.280 And they don't all scream the same way, but every 0:04:05.280 --> 0:04:06.800 once in a while, one of them is going to 0:04:06.880 --> 0:04:10.760 come along and scream like a man. And it is like, 0:04:10.840 --> 0:04:13.240 you will, you can't not laugh out loud when you 0:04:13.240 --> 0:04:15.560 see it. Every time I watched the same goat scream 0:04:15.680 --> 0:04:18.080 over and over again, and I laughed out loud every 0:04:18.120 --> 0:04:19.039 time I watched it. 0:04:19.720 --> 0:04:24.599 Yeah, and it's so non goat sounding because it's not 0:04:24.640 --> 0:04:27.200 even like a loud bleat that you wonder like, is 0:04:27.200 --> 0:04:30.359 somebody punking me? And that's just like, you know, that's 0:04:30.600 --> 0:04:33.200 James con from misery that they're looping in there. 0:04:34.240 --> 0:04:36.600 Does kind of sound like that. Another one to look 0:04:36.640 --> 0:04:39.240 up real quick, or two links in Ontario screaming at 0:04:39.279 --> 0:04:41.800 each other. It's like right in their faces. Have you 0:04:41.800 --> 0:04:42.440 seen that one? 0:04:42.680 --> 0:04:43.240 I haven't seen that. 0:04:43.440 --> 0:04:44.599 Oh, it's it's nuts. 0:04:45.920 --> 0:04:51.159 Animals well, they Well, let's just talk about why anything screams. 0:04:51.000 --> 0:04:55.360 It's a very effective tool. It's obviously a great fear 0:04:55.440 --> 0:04:58.320 response because everyone's going to sit up and take notice 0:04:58.320 --> 0:05:02.200 because it's so harsh and loud. It's a very jarring thing. 0:05:02.279 --> 0:05:07.360 It can also distract predators, obviously, screaming if you're lost, 0:05:07.480 --> 0:05:09.520 you know, scream can travel a great distance in the 0:05:09.520 --> 0:05:13.559 woods or anywhere, and you can, you know, alert somebody 0:05:13.640 --> 0:05:15.840 from a great distance. So it's a it's a great 0:05:15.920 --> 0:05:18.880 communicative tool for humans and animals alike. 0:05:19.120 --> 0:05:22.440 Yeah, and that loudness. I saw the Guinness record for 0:05:22.480 --> 0:05:26.560 the loudest scream is one hundred and twenty nine decibels, 0:05:26.600 --> 0:05:30.040 which is one decibel under a jet engine and almost 0:05:30.560 --> 0:05:32.919 in almost ten times louder than a police siren. 0:05:34.839 --> 0:05:35.599 Wonder you that was. 0:05:35.760 --> 0:05:38.240 I don't know, but man, I can't imagine that they 0:05:38.240 --> 0:05:40.960 did that too many times because, as we'll see, screaming 0:05:41.000 --> 0:05:44.040 can really mess up your your neck junk. 0:05:44.920 --> 0:05:49.760 Yeah, that's really gross. I'm getting older, so I'm getting 0:05:49.760 --> 0:05:50.880 more and more neck junk. 0:05:52.440 --> 0:05:54.039 Stress and neck chunk too. 0:05:54.880 --> 0:05:57.880 All right, So humans are are born with this ability. 0:05:58.080 --> 0:06:02.040 We know how to scream right away because we come 0:06:02.080 --> 0:06:05.320 out of the womb screaming. In fact, that's a very 0:06:05.440 --> 0:06:08.960 comforting sound when a baby is born, is that first scream. 0:06:09.000 --> 0:06:11.520 They're going to clear that flem in their airway so 0:06:11.600 --> 0:06:14.720 they can breathe. It lets everybody know, Hey, I'm here, 0:06:15.120 --> 0:06:18.400 I'm ready for action. I'm feeling good despite the fact 0:06:18.400 --> 0:06:21.680 that I'm screaming. If a baby is born and there 0:06:21.760 --> 0:06:25.640 is no scream, that is a very scary, scary moment 0:06:25.720 --> 0:06:27.920 for parents and everybody in that room. 0:06:28.080 --> 0:06:29.880 Yeah, I can imagine. It's like there the one time 0:06:29.960 --> 0:06:32.920 we're not screaming means that there's an issue. 0:06:32.960 --> 0:06:34.080 Yeah, you know, totally. 0:06:35.120 --> 0:06:37.560 And there's a lot of information in a baby's scream. 0:06:37.640 --> 0:06:41.039 It says I'm in distress, I'm in pain, I could 0:06:41.120 --> 0:06:46.240 use a gnash. There's just a lot that makes a 0:06:46.360 --> 0:06:49.080 parent because we're tuned to this kind of thing, especially 0:06:49.120 --> 0:06:52.000 if you're the parent of that baby. Studies show that 0:06:52.400 --> 0:06:56.040 you respond to your own baby's cries or screams a 0:06:56.080 --> 0:06:59.599 lot more easily or quickly than somebody who is not 0:06:59.680 --> 0:07:02.240 the parent into that baby. But you rush over there 0:07:02.279 --> 0:07:05.360 and you say, here's some food, here's a little blanket, 0:07:05.760 --> 0:07:07.840 and way to go. You just got all the phlegm 0:07:08.160 --> 0:07:10.480 out of your throat, so now you can breathe normally. 0:07:11.200 --> 0:07:13.640 Yeah. I remember when you met Ruby as a baby 0:07:13.680 --> 0:07:15.080 and she was screaming, and you're like, what the hell's 0:07:15.080 --> 0:07:15.760 wrong with this kid? 0:07:16.920 --> 0:07:19.080 Yeah? I just you know, I tried to bounce around 0:07:19.120 --> 0:07:21.560 my knee faster and it did the opposite help. 0:07:22.000 --> 0:07:25.160 And I said, oh, Josh, I'm in tune already, not 0:07:25.240 --> 0:07:28.640 in tune, tuned already. I was also in tune. And 0:07:29.040 --> 0:07:33.040 I said, that just means she's hungry. So just raise 0:07:33.040 --> 0:07:35.480 your shirt. Yeah, her what she needs. 0:07:35.520 --> 0:07:38.600 That didn't work either. She got like hair in her 0:07:38.640 --> 0:07:39.160 mouth though. 0:07:39.320 --> 0:07:42.200 Oh my god, this got really disturbing very fast. 0:07:42.280 --> 0:07:43.960 Yeah, we got it out. 0:07:44.440 --> 0:07:45.559 What about that cat cry? 0:07:46.120 --> 0:07:50.960 So, there is a a syndrome that's colloquially called I 0:07:50.960 --> 0:07:53.720 think creed a shot cry of the cat in French, 0:07:54.320 --> 0:07:57.760 and it has some similarities to down syndrome. But one 0:07:57.800 --> 0:08:00.440 of the defining characteristics of creed a shot is a 0:08:00.520 --> 0:08:04.560 larynx mauthformation, so that babies, when they cry, like the 0:08:04.720 --> 0:08:09.400 loud screaming cry, have a make us, a very specific 0:08:09.440 --> 0:08:12.960 cry that sounds very much like a cat crying. Yeah, 0:08:13.000 --> 0:08:15.600 if like you can find a couple of videos on 0:08:15.680 --> 0:08:18.240 YouTube of people with their baby with crew to a 0:08:18.320 --> 0:08:21.600 shot of crying, and it's it's really cute in a 0:08:21.600 --> 0:08:23.960 lot of ways. But also you're like, that sounds a 0:08:24.000 --> 0:08:26.720 lot like a cat, And it's so distinct that you 0:08:26.720 --> 0:08:31.520 can actually initially diagnose an infant with crewdishot syndrome because 0:08:31.560 --> 0:08:33.200 of their cry. It's that distinct. 0:08:33.840 --> 0:08:37.160 Yeah, So I mean that's a benefit that can save 0:08:37.200 --> 0:08:40.880 a lot of time and discomfort for this kid and 0:08:41.040 --> 0:08:45.120 diagnosing this kind of condition exactly, it's great. It also 0:08:45.360 --> 0:08:49.959 is a sign obviously when a kid is screaming saying hey, parent, 0:08:50.960 --> 0:08:53.560 go into fight or flight mode because I need something, 0:08:54.080 --> 0:08:57.640 and you know, if it's one of distress, even more 0:08:57.679 --> 0:09:00.760 so obviously and not just like I'm hungry, like beer distress. 0:09:01.840 --> 0:09:04.320 I don't know that we need to discuss fighter flight 0:09:04.360 --> 0:09:07.400 in detail because we did it three hundred and sixty 0:09:07.400 --> 0:09:10.320 four times over the first like five years of the show, right, 0:09:10.920 --> 0:09:13.679 but everyone knows what that is, right, Yeah, I. 0:09:13.600 --> 0:09:15.280 Would think, so, I don't think we really need to 0:09:15.320 --> 0:09:16.400 describe fight or flight. 0:09:17.280 --> 0:09:19.560 You're like, uh, but it's uh, I didn't. 0:09:19.600 --> 0:09:26.080 I stopped myself. I exercise a great restraint. Nice work, Okay, Well, anyway, 0:09:26.120 --> 0:09:28.760 I'll take it from here, Chuck. Yeah, because the reason 0:09:28.800 --> 0:09:31.720 you brought that up is screams activate fireflight mode in 0:09:31.760 --> 0:09:35.560 some really like basic ways, as we'll see. And so 0:09:35.640 --> 0:09:38.600 a scream actually activates in you a human who hears 0:09:38.640 --> 0:09:41.880 a scream, that that readiness to like either spring into 0:09:41.960 --> 0:09:46.240 action or run like hell or freeze or fawn is 0:09:46.280 --> 0:09:50.360 the other one now, because the fight or flight syndromes 0:09:50.400 --> 0:09:52.560 really come a long way since we last talked about it, 0:09:52.800 --> 0:09:55.600 And fawn is the response that you want when a 0:09:55.679 --> 0:09:57.920 baby's crying. You want to go over and be like, oh, 0:09:57.960 --> 0:09:58.880 it's okay. 0:09:59.480 --> 0:10:04.280 Yeah, that's here. Never mind abandoned that line of thought. 0:10:05.679 --> 0:10:08.400 So let's talk about sound for a minute. Because all 0:10:08.480 --> 0:10:13.440 sound comes from and is perceived by us through a 0:10:13.520 --> 0:10:18.000 series of processes in the brain, and most of these 0:10:18.160 --> 0:10:21.240 are in the higher brain region. But screams are different. 0:10:21.679 --> 0:10:26.520 They happen in the lower brain region. And it's a 0:10:26.600 --> 0:10:29.000 very interesting thing. It kind of lives in its own 0:10:29.120 --> 0:10:31.839 as far as like humans making sound lives in its 0:10:31.840 --> 0:10:34.199 own area. It's very distinct from all the other sounds 0:10:34.200 --> 0:10:34.560 we make. 0:10:34.679 --> 0:10:38.840 Yeah, and it's a lot faster to basically activate us 0:10:38.920 --> 0:10:41.800 than the normal speech that we hear. Right, So when 0:10:41.840 --> 0:10:45.720 you talk, when you're making just talk like I am 0:10:45.800 --> 0:10:49.480 right now, say this is a good example. I'm using 0:10:49.559 --> 0:10:53.080 this description as an example in real time. Okay, that's right. 0:10:53.160 --> 0:10:56.800 So I'm using my laryngeal motor cortex that's basically running 0:10:56.840 --> 0:11:00.320 the show right now, and that is a higher brain process. Right, 0:11:00.400 --> 0:11:04.360 So I'm using cognition. I'm figuring out how my mouse 0:11:04.360 --> 0:11:08.600 should move, which also requires fine motor coordination and processing sound. 0:11:09.240 --> 0:11:13.080 I think from our Internal Dialogue episode, I'm doing a 0:11:13.120 --> 0:11:16.360 quick quality check right before I actually say the words 0:11:16.679 --> 0:11:19.640 yeah and Josh exactly, and do I sound like a 0:11:19.720 --> 0:11:24.040 muppety tenor I do, let's go. And then this stuff 0:11:24.120 --> 0:11:26.400 is sent to the brain stem, which basically says, okay, 0:11:26.480 --> 0:11:30.040 laryings and vocal cords and lungs and abdominal muscles, let's talk. 0:11:30.520 --> 0:11:33.559 That's normal speech. And again it requires a lot of 0:11:33.640 --> 0:11:39.559 higher brain processing. Screaming uses a different set of equipment 0:11:39.720 --> 0:11:43.720 to make itself happen. It's nuts because you think screaming 0:11:43.800 --> 0:11:47.000 is a form of speech. It's actually not. Even though 0:11:47.040 --> 0:11:50.360 we use a lot of the same stuff, a lot 0:11:50.360 --> 0:11:54.160 of the same bait and tackle, say like it's its 0:11:54.160 --> 0:11:56.560 own thing, which is I just find this is where 0:11:56.559 --> 0:11:58.520 I'm like, Okay, this is super fascinating. 0:11:58.559 --> 0:12:02.960 Now, yeah, that's right. So for screams, uh, and some 0:12:03.080 --> 0:12:07.000 involuntary vocalizations, but really screams, the sound production takes a 0:12:07.040 --> 0:12:10.040 different and, like you said, a much faster path. The 0:12:10.040 --> 0:12:12.880 signal starts in the limbic system and it skips that 0:12:12.960 --> 0:12:18.400 higher brain processing. Uh. The it happens in the amygdala. Basically, 0:12:18.440 --> 0:12:23.040 the emotional stimulus that the amygdala is all about just 0:12:23.080 --> 0:12:25.040 sends a scream signal. It's it's sort of like a 0:12:25.080 --> 0:12:29.719 direct path, like a express train through that brain stem 0:12:30.240 --> 0:12:32.600 to all the anatomy that you were talking about in 0:12:32.679 --> 0:12:35.080 your in your the you know, the neck junk, and 0:12:35.120 --> 0:12:39.120 that scream just comes out immediately. And the craziest part 0:12:39.320 --> 0:12:43.760 is our body actually picks up on this before our 0:12:44.200 --> 0:12:46.800 ears and brain can even process what we've just heard. 0:12:46.960 --> 0:12:50.000 Yeah, once the scream comes out of someone else, when 0:12:50.040 --> 0:12:52.880 we hear that scream, it puts us in fight or 0:12:52.880 --> 0:12:56.160 flight mode before we're even consciously aware that we have 0:12:56.280 --> 0:13:00.160 heard a scream. That's how that's how finely tuned we 0:13:00.200 --> 0:13:03.800 are too responding to screams, which again, this is something 0:13:03.920 --> 0:13:06.160 you just think exists out there, and then when you 0:13:06.200 --> 0:13:08.760 dig in, you're like, my god. So there's like a 0:13:09.679 --> 0:13:14.400 whole set of processes that take place that again are 0:13:14.480 --> 0:13:18.400 different than how we would respond if we hear regular speech, right, 0:13:18.640 --> 0:13:20.960 So it follows some of the same processes. It hits 0:13:20.960 --> 0:13:23.679 the outer ear, goes through the ear canal, the ear 0:13:23.760 --> 0:13:28.080 drum goes boom boom. That is amplified in the middle ear, 0:13:28.160 --> 0:13:30.920 and that goes onto the cochlia, which triggers a wave 0:13:30.960 --> 0:13:33.760 along the basel or membrane, which says, I'm going to 0:13:33.840 --> 0:13:36.280 turn this into an electrical signal, sends it to the 0:13:36.320 --> 0:13:39.280 auditory nerve, which sends it to the brain stem and 0:13:39.320 --> 0:13:42.199 then to the thalamus. And the thalamus is the sensory 0:13:42.600 --> 0:13:45.400 clearing house. It sends this to that and that to that. 0:13:45.679 --> 0:13:48.200 All of your sensory information goes to the thalamus. And 0:13:48.320 --> 0:13:51.920 here is where it diverges from normal speech. 0:13:52.679 --> 0:13:55.599 Yeah, And I mean that's why when somebody screams, like 0:13:55.640 --> 0:13:59.440 a blood curling scream out in public, you're instantly reacting. 0:13:59.440 --> 0:14:02.120 You don't hear that and then decide like, well, maybe 0:14:02.120 --> 0:14:04.280 I should go see what's going on over there, Like 0:14:04.320 --> 0:14:08.120 your body is instantly reacting because it is unconsciously picked 0:14:08.160 --> 0:14:11.240 up on that screen before it's even registered in your brain. 0:14:11.320 --> 0:14:17.079 So it's really a pretty remarkable sort of evolutionary trait. 0:14:17.120 --> 0:14:21.000 I think, like to help rescue, you know, probably back 0:14:21.000 --> 0:14:25.720 in Tiktook's days, the wife or baby that the husband 0:14:25.720 --> 0:14:28.480 who's out hunting and gathering has to protect from whatever 0:14:28.640 --> 0:14:30.440 dangers are around the fire. 0:14:30.680 --> 0:14:33.480 Yeah, And the reason why that happens is because when 0:14:33.520 --> 0:14:36.160 it hits that balance, it gets sent two different ways. Like, 0:14:36.200 --> 0:14:39.520 it gets sent the normal way to that higher brain processing, 0:14:39.800 --> 0:14:42.480 and when it goes through that higher brain processing, that's 0:14:42.520 --> 0:14:45.960 when you become conscious of hearing that scream. But what's 0:14:46.000 --> 0:14:49.200 happened even faster is it got sent to that amygdala 0:14:49.280 --> 0:14:53.560 and that sent in the fight or flight response, and 0:14:53.760 --> 0:14:57.080 that happened before your higher brain finished processing, which is 0:14:57.200 --> 0:15:03.800 just so there's this own pathway for just screams that 0:15:03.200 --> 0:15:09.440 the human brain has evolved to basically make you able 0:15:09.480 --> 0:15:12.880 to respond to a scream faster. It has its own expressway. 0:15:13.320 --> 0:15:16.200 Screams only essentially, is what it says, and if your 0:15:16.440 --> 0:15:20.040 regular speech you try to use that same expressway. It's 0:15:20.080 --> 0:15:23.560 got those tire bursting spikes that will just stop you 0:15:23.680 --> 0:15:27.000 cold right there, and they'll send you back along the 0:15:27.040 --> 0:15:29.160 way you're supposed to go to the higher brain. 0:15:29.640 --> 0:15:31.920 You go back to talk toown buddy exactly. 0:15:32.240 --> 0:15:34.080 And it's gonna take you a while to get there 0:15:34.160 --> 0:15:36.760 because you don't have tires. You're driving on just rims 0:15:36.800 --> 0:15:39.600 now because you were domin made a poor decision. 0:15:40.040 --> 0:15:41.760 Yeah, and you shouldn't do that because you're gonna damage 0:15:41.760 --> 0:15:43.360 those rims. You need to pull over immediately. 0:15:43.400 --> 0:15:43.920 Yeah. Bad. 0:15:44.760 --> 0:15:45.680 Should we take a break? 0:15:46.040 --> 0:15:46.760 Yeah? I think so. 0:15:47.240 --> 0:15:49.280 All right, we're gonna take a break and come back, 0:15:49.320 --> 0:15:52.280 and Josh is gonna explain something called the roughness domain 0:15:52.640 --> 0:15:53.200 right after this. 0:16:27.600 --> 0:16:30.120 All right, chuck, here we go. Here's the flubbing. 0:16:31.120 --> 0:16:33.320 Okay, well we'll see. It's a little brain breaking, but 0:16:34.000 --> 0:16:34.520 we'll get it. 0:16:34.840 --> 0:16:36.720 I think it's one of those things where if I 0:16:37.160 --> 0:16:38.880 just thought too hard about it and I've made it 0:16:38.880 --> 0:16:43.600 brain breaking. But so, screams have something in common, and 0:16:43.640 --> 0:16:47.800 that is that they exist in a region of human 0:16:47.840 --> 0:16:53.400 perception that's called the roughness domain. Okay, And if you 0:16:53.560 --> 0:16:59.720 take someone's voice right, it has a certain frequency. My 0:16:59.800 --> 0:17:02.480 voice has a certain frequency. You can recognize it as mine. 0:17:02.920 --> 0:17:07.040 But you can take my voice and make it modulate, right, 0:17:07.119 --> 0:17:11.560 So like the British police car that goes. 0:17:11.480 --> 0:17:13.399 Dude, do do do do doo? 0:17:13.760 --> 0:17:18.640 That's modulating right. So it has its own its own frequency, right, 0:17:19.200 --> 0:17:23.080 but you're making it change pitch do do do do? 0:17:23.560 --> 0:17:27.280 So that's a second frequency that it has. And if 0:17:27.320 --> 0:17:30.359 that frequency is between thirty hurts and one hundred and 0:17:30.359 --> 0:17:34.400 fifty hertz, that modulation between up and down or left 0:17:34.400 --> 0:17:36.600 and right, however you want to look at it. That 0:17:36.760 --> 0:17:40.280 is that roughness area. And it also seems to be 0:17:40.400 --> 0:17:44.960 reserved as far as human sounds go, just for screams. 0:17:45.800 --> 0:17:48.879 Yeah, there was a study. They learned this because of 0:17:48.920 --> 0:17:49.720 a study. 0:17:49.640 --> 0:17:50.359 We how'd I do? 0:17:51.200 --> 0:17:53.359 Oh? You'd a great? Okay kid, I'm sorry I didn't 0:17:53.680 --> 0:17:54.919 the customary thank you. 0:17:55.720 --> 0:17:57.760 We usually edit the colaps out. I think we should 0:17:57.840 --> 0:17:58.320 leave that one in. 0:17:58.400 --> 0:18:00.479 Yeah, yeah, let's leave that one in. They know this 0:18:00.520 --> 0:18:04.600 because in twenty fifteen NYU, the neuroscientists, theyre published a 0:18:04.640 --> 0:18:11.000 study supporting this role of amplitude modulation. And the crazy 0:18:11.040 --> 0:18:13.960 part is that the only other sound in that rough 0:18:14.000 --> 0:18:18.200 this domain, like that's the only sound a human can make. 0:18:18.359 --> 0:18:22.160 That's like that. The only other sounds are all artificial alarms. 0:18:22.600 --> 0:18:26.040 So the human screen lives in the roughest domain alongside 0:18:26.440 --> 0:18:31.560 sirens and car alarms and you know, just other other 0:18:31.720 --> 0:18:34.600 like claxon. Maybe what is that? 0:18:34.840 --> 0:18:36.400 Is that the bad guys in Doctor Who? 0:18:36.960 --> 0:18:40.480 I think a claxon is the Eh? 0:18:40.520 --> 0:18:42.680 Oh those are terrible, like pull your credit card out 0:18:42.720 --> 0:18:43.639 of the card terminal. 0:18:44.520 --> 0:18:45.399 Does it actually do that? 0:18:45.520 --> 0:18:48.719 Yes, so they did originally. I think they've kind of stopped, 0:18:48.760 --> 0:18:50.320 but it would used to be really jarring. 0:18:51.520 --> 0:18:54.040 Yeah, I mean, because that's the sound that happens when 0:18:54.040 --> 0:18:57.040 a nuclear facility is melting down. 0:18:57.160 --> 0:19:00.159 Right, forget your credit card, melt on a nuclear facility, 0:19:00.480 --> 0:19:01.920 basically the same thing. 0:19:03.040 --> 0:19:04.720 Yeah, So thanks NYU for that. Right. 0:19:04.880 --> 0:19:07.920 Well, okay, that was just part one of this study. 0:19:08.000 --> 0:19:10.880 This is a really robust study. So they analyzed recorded 0:19:10.920 --> 0:19:14.080 sounds and they found that screams were all in roughness 0:19:14.080 --> 0:19:16.840 and the only other sounds that were in there were alarms. Right. 0:19:17.480 --> 0:19:22.080 Then they got a bunch of volunteers, almost guaranteed NYU 0:19:22.160 --> 0:19:25.320 undergrads looking for extra credit, and they said, we want 0:19:25.359 --> 0:19:27.159 you to make a bunch of sounds. We want you 0:19:27.200 --> 0:19:30.120 to scream, we want you to speak normally, we want 0:19:30.160 --> 0:19:34.439 you to scream speak yeah, and make a bunch of 0:19:34.560 --> 0:19:39.280 meaningless vocalizations like yips, yammers, yelps, that whole thing, right, sure, 0:19:39.600 --> 0:19:42.320 And then they analyzed those just like they analyzed the 0:19:42.359 --> 0:19:44.639 recorded sounds, and they found that all of the scream 0:19:44.720 --> 0:19:47.919 sounds were in the roughness domain, and all of the 0:19:48.040 --> 0:19:52.320 non scream sounds, including yips and yamers, were not in 0:19:52.359 --> 0:19:55.800 the roughness domain whatsoever. So they're really zeroing in. And 0:19:55.880 --> 0:19:58.840 yet there's more to this study. This is how robust 0:19:58.880 --> 0:19:59.199 it was. 0:20:00.119 --> 0:20:02.040 Yeah. So then they said, all right, we got all 0:20:02.080 --> 0:20:05.280 this collection of sounds, neutral sounds is what we'll call, 0:20:05.320 --> 0:20:08.000 the ones that aren't screams, and then the screamy things. 0:20:08.440 --> 0:20:11.840 And they brought in some other volunteers, other NYU students 0:20:11.920 --> 0:20:14.359 for sure, and said, all right, we want you to 0:20:14.440 --> 0:20:17.119 rate the scariness like maybe on a one to ten, 0:20:17.280 --> 0:20:19.679 one to five, who knows what they used, maybe a 0:20:19.800 --> 0:20:23.280 Yelp star system, and they said, rate the scariness of 0:20:23.320 --> 0:20:26.960 the sounds. All the sounds in the roughness domain. This 0:20:27.000 --> 0:20:29.879 is pretty obvious. We're rated as scarier than the neutral sounds. 0:20:30.680 --> 0:20:32.960 And the sounds that were rated the scariest were the 0:20:32.960 --> 0:20:35.119 ones that were highest on the roughness scale. 0:20:35.240 --> 0:20:37.920 All makes sense, right, So they're really drilling down here. 0:20:38.000 --> 0:20:43.040 It keeps going, everybody. They actually took volunteers, probably the 0:20:43.080 --> 0:20:45.760 same ones who rated the scariness of the sounds, and 0:20:45.800 --> 0:20:48.720 they scanned them while they were listening to scary sounds 0:20:49.040 --> 0:20:52.240 and not just screamed but also the artificial alarms too, 0:20:52.720 --> 0:20:56.800 and probably some of the nonsense sounds and musical sounds, 0:20:57.400 --> 0:21:01.320 And as they were listening, the scream and the alarms 0:21:01.359 --> 0:21:04.800 were the only ones that cause spikes in the amygdala. Remember, 0:21:04.840 --> 0:21:09.520 the amygdala is where that set aside pathway for screams is, 0:21:10.359 --> 0:21:13.320 and that the higher on the roughness scale, if you 0:21:13.320 --> 0:21:15.280 can call it that, that the screams or alarms were, 0:21:15.600 --> 0:21:19.960 the greater the amygdala activity, and then the greater the 0:21:20.000 --> 0:21:23.760 amygdala activity that was shown in the scans, the higher 0:21:24.000 --> 0:21:28.600 those sounds had been rated for scariness by the volunteers previously. 0:21:29.119 --> 0:21:31.200 And when they wrapped it up and put all this together, 0:21:31.720 --> 0:21:34.000 they were like, I forgot what we were studying in 0:21:34.040 --> 0:21:34.800 the first place. 0:21:38.280 --> 0:21:43.280 So the upshot, to borrow a term from Josh, is 0:21:43.320 --> 0:21:49.800 that it seems like humans are specifically attuned and our 0:21:49.800 --> 0:21:54.160 amygdala is specifically activated by the sound of a scream, 0:21:55.080 --> 0:21:58.480 to say like, hey, it's time to panic or it's 0:21:58.520 --> 0:22:01.800 time to kick into high gear. They found that this 0:22:01.960 --> 0:22:06.120 works if you're awake or asleep. Yeah, at the rough 0:22:06.200 --> 0:22:08.760 vocalizations and that rough domain that we were talking about 0:22:08.800 --> 0:22:14.320 penetrate human sleep cycles more than neutral vocalizations. And that's 0:22:14.359 --> 0:22:18.040 not to say that like, yeah, of course it's louder, dummy. 0:22:18.200 --> 0:22:20.439 We're not talking about decibels here, We're talking about a 0:22:20.520 --> 0:22:24.040 frequency range. Like I think what they're saying and correct 0:22:24.080 --> 0:22:26.479 me if I'm wrong, is that is that a scream 0:22:26.520 --> 0:22:28.439 that might be the same decibel level as like a 0:22:28.480 --> 0:22:31.879 really loud talk will penetrate that sleep cycle unlike that 0:22:31.920 --> 0:22:32.600 really loud talk. 0:22:32.760 --> 0:22:35.879 Yes, And they think it's because the amygdala is tuned 0:22:35.920 --> 0:22:38.760 to that thirty to one hundred and fifty hertz rightness band. 0:22:39.280 --> 0:22:42.199 So the amygdala has its own route for getting you 0:22:42.280 --> 0:22:45.760 aroused and not necessarily in the best way when you 0:22:45.840 --> 0:22:48.359