1 00:00:01,920 --> 00:00:06,400 Speaker 1: Welcome to brain Stuff production of I Heart Radio, Hey 2 00:00:06,440 --> 00:00:09,800 Speaker 1: brain Stuff, Lauren Vogel Bomb here. The larynx may not 3 00:00:09,920 --> 00:00:12,879 Speaker 1: get the same amount of attention as the heart or lungs, 4 00:00:12,880 --> 00:00:16,680 Speaker 1: but it's still an important internal organ nestled in the 5 00:00:16,720 --> 00:00:20,120 Speaker 1: necks of people and other animals. The larynx helps allow 6 00:00:20,160 --> 00:00:24,079 Speaker 1: for noisemaking and speech, and is located below the epiglottis, 7 00:00:24,239 --> 00:00:27,000 Speaker 1: which is the leaf shaped flap that prevents choking by 8 00:00:27,080 --> 00:00:30,720 Speaker 1: keeping food and drink out of the lungs. Part of 9 00:00:30,720 --> 00:00:34,400 Speaker 1: the larynx structure includes the voice box, also sometimes referred 10 00:00:34,440 --> 00:00:37,519 Speaker 1: to as the vocal chords. It's what makes up the 11 00:00:37,560 --> 00:00:39,760 Speaker 1: bump that you can see and feel in the middle 12 00:00:39,800 --> 00:00:43,839 Speaker 1: of your neck, scientifically known as the laryngeal prominence, but 13 00:00:44,080 --> 00:00:47,919 Speaker 1: more commonly called the Adam's apple. Women have one too, 14 00:00:48,240 --> 00:00:52,320 Speaker 1: just often less pronounced. During childhood, the voice boxes of 15 00:00:52,360 --> 00:00:55,040 Speaker 1: boys and girls are about the same size, but when 16 00:00:55,080 --> 00:00:57,840 Speaker 1: most boys hit their tween and teen years, their vocal 17 00:00:57,880 --> 00:01:01,560 Speaker 1: chords hit a growth spurt. The growth causes their voices 18 00:01:01,560 --> 00:01:04,479 Speaker 1: to crack and eventually results in a deeper and more 19 00:01:04,520 --> 00:01:09,640 Speaker 1: resonant tone. So let's look at how the voice box 20 00:01:09,760 --> 00:01:14,399 Speaker 1: or vocal chords work. First off, neither moniker is really accurate. 21 00:01:14,920 --> 00:01:18,440 Speaker 1: The vocal chords are actually two bands of flexible, smooth 22 00:01:18,480 --> 00:01:21,440 Speaker 1: muscle tissue that are located in the larynx, and these 23 00:01:21,520 --> 00:01:24,440 Speaker 1: muscles vibrate as air moves through them on its way 24 00:01:24,480 --> 00:01:28,399 Speaker 1: to or from the lungs. They're more properly called folds 25 00:01:28,520 --> 00:01:32,919 Speaker 1: instead of chords. We spoke via email with gi Zeppe 26 00:01:33,000 --> 00:01:37,360 Speaker 1: Araguna m D. He explained during sound production, the vocal 27 00:01:37,360 --> 00:01:40,959 Speaker 1: folds closed together and start vibrating as air is expelled 28 00:01:41,000 --> 00:01:43,840 Speaker 1: from the lungs and passes between them and into your mouth, 29 00:01:44,200 --> 00:01:46,360 Speaker 1: which helps to make the sounds we hear when we're 30 00:01:46,360 --> 00:01:50,800 Speaker 1: listening to people talk. So, the larynx is made up 31 00:01:50,840 --> 00:01:54,680 Speaker 1: of a cartilage skeleton that contains the vocal folds covered 32 00:01:54,720 --> 00:01:58,240 Speaker 1: by a mucous lining. The folds are extremely adept at 33 00:01:58,280 --> 00:02:01,640 Speaker 1: changing shape, position, and mention, so the voice can make 34 00:02:01,680 --> 00:02:04,720 Speaker 1: a range of sounds at a variety of levels. If 35 00:02:04,760 --> 00:02:07,960 Speaker 1: the larynx becomes inflamed because of illness or injury, the 36 00:02:08,040 --> 00:02:12,040 Speaker 1: vocal chords can swell and cause laryngitis, which is characterized 37 00:02:12,040 --> 00:02:15,160 Speaker 1: by a hoarse, gravelly sounding voice or the loss of 38 00:02:15,160 --> 00:02:19,520 Speaker 1: one's voice altogether. But we also spoke by email with 39 00:02:19,560 --> 00:02:23,040 Speaker 1: Taylor Graber m d. He said, if they're swelling to 40 00:02:23,080 --> 00:02:26,919 Speaker 1: a vocal chord from overuse, cancers, or trauma, the tone 41 00:02:26,960 --> 00:02:30,440 Speaker 1: and function produced by the vocal cord becomes altered. The 42 00:02:30,480 --> 00:02:33,520 Speaker 1: sounds can also change by injury to the muscles or 43 00:02:33,560 --> 00:02:36,480 Speaker 1: to the nerves that innervate or give sensation to the 44 00:02:36,560 --> 00:02:41,320 Speaker 1: vocal chords. However, there are several sounds that we can 45 00:02:41,360 --> 00:02:46,400 Speaker 1: produce without a larynx, even speech via whispering. When you whisper, 46 00:02:46,560 --> 00:02:50,160 Speaker 1: the vocal chords can stay slack and not vibrate. But 47 00:02:50,280 --> 00:02:52,960 Speaker 1: this is known as an open throat whisper, and it 48 00:02:53,000 --> 00:02:56,320 Speaker 1: allows people who are mute to make sound. It's also 49 00:02:56,360 --> 00:02:59,160 Speaker 1: a helpful technique for people who are resting their voices, 50 00:02:59,200 --> 00:03:02,400 Speaker 1: such as singers sore those with a sore throat. However, 51 00:03:02,720 --> 00:03:06,960 Speaker 1: most people don't use this passive technique when they whisper. Instead, 52 00:03:07,040 --> 00:03:09,760 Speaker 1: they strain to produce a sound, and this can be 53 00:03:09,840 --> 00:03:14,480 Speaker 1: just as harmful to the vocal cords as shouting. But hey, 54 00:03:14,520 --> 00:03:17,959 Speaker 1: if humans and other animals all have a larynx, then 55 00:03:18,000 --> 00:03:22,720 Speaker 1: why is speaking a uniquely human ability. Our brain formation 56 00:03:22,760 --> 00:03:25,240 Speaker 1: has something to do with it, but people have an 57 00:03:25,360 --> 00:03:29,600 Speaker 1: especially complex system comprising the larynx which produces sound, and 58 00:03:29,840 --> 00:03:33,960 Speaker 1: a flexible mouth, tongue, and lips that, in combination, allows 59 00:03:34,040 --> 00:03:38,040 Speaker 1: us to generate the precise sounds that language requires. When 60 00:03:38,040 --> 00:03:40,880 Speaker 1: we talk, air moves from the lungs through the larynx, 61 00:03:40,920 --> 00:03:44,040 Speaker 1: and that sound is shaped by the extreme fine motor 62 00:03:44,080 --> 00:03:48,920 Speaker 1: control found in the throat, mouth, tongue, and lips. We 63 00:03:49,000 --> 00:03:51,840 Speaker 1: also have a bone called the highoid. This is a 64 00:03:51,960 --> 00:03:54,720 Speaker 1: U shaped bone situated at the front of throat above 65 00:03:54,760 --> 00:03:58,280 Speaker 1: the larynx. According to Graber, he said it forms the 66 00:03:58,280 --> 00:04:01,200 Speaker 1: attachment from multiple muscles and the neck, which aid in 67 00:04:01,320 --> 00:04:06,800 Speaker 1: tongue movement and swallowing. What's really unusual about this larynx 68 00:04:06,800 --> 00:04:09,480 Speaker 1: related bone is that it has the distinction of being 69 00:04:09,480 --> 00:04:12,160 Speaker 1: the only bone in the human body that's free floating, 70 00:04:12,520 --> 00:04:15,720 Speaker 1: which means it isn't connected to any other bone. Instead, 71 00:04:15,800 --> 00:04:19,559 Speaker 1: it's supported by connective tissue. The hyoid is only found 72 00:04:19,560 --> 00:04:22,080 Speaker 1: in humans and Neanderthals and is believed to be the 73 00:04:22,120 --> 00:04:26,679 Speaker 1: foundation of our ability to speak. There are about sixty 74 00:04:27,040 --> 00:04:29,560 Speaker 1: people in the United States who have had their larynx removed, 75 00:04:29,680 --> 00:04:32,440 Speaker 1: but only a few who have had a larynx transplant. 76 00:04:32,880 --> 00:04:35,680 Speaker 1: A few people qualify, and if they do, the surgery 77 00:04:35,760 --> 00:04:38,960 Speaker 1: is complex that takes about eighteen hours, and is hampered 78 00:04:39,000 --> 00:04:44,039 Speaker 1: by shortage of larynx available to transplant. However, new initiatives, 79 00:04:44,120 --> 00:04:47,159 Speaker 1: including lap grown and three D printed larynx, have the 80 00:04:47,160 --> 00:04:55,880 Speaker 1: potential to help people recover their own voices again. Today's 81 00:04:55,880 --> 00:04:58,040 Speaker 1: episode was written by Laurie al Dove and produced by 82 00:04:58,040 --> 00:05:00,280 Speaker 1: Tyler Klang. For more in this and not of other 83 00:05:00,360 --> 00:05:03,559 Speaker 1: craft topics, visit how stuff works dot com. Brain Stuff 84 00:05:03,600 --> 00:05:06,080 Speaker 1: is production of I Heart Radio or more podcasts. My 85 00:05:06,120 --> 00:05:09,040 Speaker 1: heart Radio visit the iHeart Radio app, Apple Podcasts, or 86 00:05:09,080 --> 00:05:10,880 Speaker 1: wherever you listen to your favorite shows.