WEBVTT - BrainStuff Classics: Why Do Men Have Deeper Voices? 0:00:02.040 --> 0:00:07.120 Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff, 0:00:07.120 --> 0:00:09.960 I'm Lauren voc Obam, and today's episode is another brain 0:00:10.039 --> 0:00:13.680 Stuff classic from our erstwhile host, Christian Sager. Our question 0:00:13.720 --> 0:00:16.319 for the day, why do men tend to have deeper 0:00:16.440 --> 0:00:23.680 voices than women? Hello, brain Stuff, I'm Christian Saga, and 0:00:23.800 --> 0:00:26.920 today we're going to talk about the human voice. You 0:00:27.000 --> 0:00:29.280 might have noticed that if you're talking to a group 0:00:29.280 --> 0:00:32.080 of five year old boys and girls, let's say you're 0:00:32.120 --> 0:00:35.640 asking them for advice about your investment portfolio, there's not 0:00:35.800 --> 0:00:38.839 a big difference between the pitch of the girl's voices 0:00:38.920 --> 0:00:42.000 and the pitch of the boys voices. Yet if you 0:00:42.120 --> 0:00:44.640 talk to a group of thirty five year old men 0:00:44.680 --> 0:00:47.839 and women, you notice that the men's voices are on 0:00:48.200 --> 0:00:51.800 average a good bit deeper than the women's voices. So 0:00:51.960 --> 0:00:54.959 why is that and how does it happen? Well, first off, 0:00:55.040 --> 0:00:59.000 let's acknowledge that everyone is a special and unique butterfly, 0:00:59.400 --> 0:01:02.040 and there's no rule about how men and women's voices 0:01:02.080 --> 0:01:06.960 should sound. But on average, adult men's voices have what's 0:01:07.000 --> 0:01:12.080 known as a lower fundamental frequency than adult women's voices. 0:01:12.400 --> 0:01:16.400 The fundamental frequency is simply the scientific term for how 0:01:16.480 --> 0:01:21.000 high or low a person's natural speaking voice sounds. Sound 0:01:21.000 --> 0:01:24.080 frequency is measured in hurts, which is a measure of 0:01:24.120 --> 0:01:27.679 how many times something happens in a second. So a 0:01:27.800 --> 0:01:31.000 sound wave that vibrates a hundred times per second produces 0:01:31.040 --> 0:01:34.360 a tone of a hundred hurts. The more cycles per second, 0:01:34.520 --> 0:01:37.440 the higher the pitch. According to the National Center for 0:01:37.600 --> 0:01:41.280 Voice and Speech, babies usually cry at a frequency of 0:01:41.319 --> 0:01:45.720 around five hundred hurts. Children have speaking frequencies in the 0:01:45.840 --> 0:01:48.680 range of two hundred and fifty to four hundred hurts 0:01:48.680 --> 0:01:52.280 by the time of adulthood. However, men have an average 0:01:52.360 --> 0:01:56.640 fundamental frequency of about one hundred and twenty five hurts 0:01:56.640 --> 0:02:00.120 and women about two hundred hurts. What happened here? What? 0:02:00.360 --> 0:02:04.200 Why the big difference? Okay, to understand why men's voices 0:02:04.320 --> 0:02:06.680 end up lower than women's voices, we need to look 0:02:06.720 --> 0:02:09.520 at how the body produces sounds. So let's take a 0:02:09.600 --> 0:02:13.480 magical journey to the inside of your neck. Leading from 0:02:13.520 --> 0:02:16.000 your lungs to the cavity behind your mouth and nose 0:02:16.120 --> 0:02:18.800 is a pipeline called the tray chia. You use it 0:02:18.840 --> 0:02:21.120 to breathe. At the top of the trachea is a 0:02:21.160 --> 0:02:24.680 hollow organ called the larynx, or in common parlance, the 0:02:24.800 --> 0:02:28.440 voice box. The larynx is amazing. For example, when you 0:02:28.480 --> 0:02:31.200 swallow food, it is a part of the larynx called 0:02:31.200 --> 0:02:34.560 the epiglottis that closes off your tray chia and keeps 0:02:34.560 --> 0:02:37.880 you from getting gummy bears in your lungs. The larynx 0:02:37.960 --> 0:02:40.720 is also what allows us to make sound for talking 0:02:40.840 --> 0:02:43.160 or singing. To do this, you use your lungs to 0:02:43.200 --> 0:02:45.760 push a column of air through the larynx while using 0:02:45.760 --> 0:02:49.640 your laryngeal muscles to press together a pair of membranes 0:02:49.720 --> 0:02:54.239 called the vocal folds, or more commonly, your vocal chords. 0:02:54.639 --> 0:02:57.480 When you close the vocal folds like this, the air 0:02:57.560 --> 0:03:01.639 you push out through them makes them vibrate, and this 0:03:01.760 --> 0:03:05.200 vibration leads to sound. So the next time you're just 0:03:05.280 --> 0:03:09.240 shrieking and shrieking until the cashier finally accepts your expired coupon, 0:03:09.760 --> 0:03:13.280 thank your larynx. There are several factors that can all 0:03:13.320 --> 0:03:16.919 have some effect on the fundamental frequency of a person's voice, 0:03:17.000 --> 0:03:20.280 like the size of the larynx and the differential development 0:03:20.320 --> 0:03:24.359 of facial bones and muscles. But the most important factor 0:03:24.400 --> 0:03:27.440 to talk about is the length of the vocal folds. 0:03:27.840 --> 0:03:30.519 If you pluck a string, the length of the string 0:03:30.600 --> 0:03:33.880 affects the frequency of the note that plays. Think about 0:03:33.880 --> 0:03:36.520 a guitar. When you press a string down to a 0:03:36.600 --> 0:03:39.400 higher fret. On a guitar, you shorten the length of 0:03:39.440 --> 0:03:41.880 the part of the string that vibrates when you pluck it, 0:03:42.240 --> 0:03:45.600 and this produces a higher note. The same thing happens 0:03:45.640 --> 0:03:48.920 inside your larynx. The longer the vocal fold, the lower 0:03:48.960 --> 0:03:52.920 the note. During puberty, both boys and girls experience growth 0:03:53.040 --> 0:03:56.320 of the vocal folds, leading to lower voices, but the 0:03:56.360 --> 0:04:01.640 male hormone testosserone, which is released by the testicles during puberty, 0:04:01.760 --> 0:04:06.160 typically causes boys vocal folds to grow longer and thicker 0:04:06.200 --> 0:04:10.000 than girls. On average, adult women have vocal folds somewhere 0:04:10.040 --> 0:04:13.600 around ten millimeters long, while adult men have vocal folds 0:04:13.600 --> 0:04:18.320 in the neighborhood of sixteen millimeters. Consequently, women are up 0:04:18.360 --> 0:04:21.680 there on the upper frets, soloing into oblivion like a 0:04:21.720 --> 0:04:24.560 high school kid who just learned how to play eruption 0:04:24.640 --> 0:04:28.000 by Van Halen, and men are letting the open strings 0:04:28.080 --> 0:04:31.920 ring like the intro of nothing else matters by Metallica. 0:04:32.279 --> 0:04:35.279 Now here's some bonus information for you. Everyone knows what 0:04:35.400 --> 0:04:38.360 happens when you inhale some helium from a party balloon 0:04:38.480 --> 0:04:41.520 or you know, straight from an industrial helium transport truck. 0:04:42.000 --> 0:04:45.680 Your voice pitch gets higher. This is because helium is 0:04:45.800 --> 0:04:48.560 less dense than air. But did you know you can 0:04:48.600 --> 0:04:52.320 reverse the effect and give yourself a deep, booming bridge 0:04:52.360 --> 0:04:55.880 troll voice by breathing a gas with a higher density 0:04:55.920 --> 0:05:00.479 than your air, like zenon or sulfur hexafloor a ride. 0:05:00.720 --> 0:05:03.640 But remember, your body needs air to live, and breathing 0:05:03.640 --> 0:05:06.640 anything other than air can be dangerous, so don't try 0:05:06.680 --> 0:05:13.440 this at home. Today's episodes written by Joe McCormick and 0:05:13.440 --> 0:05:16.040 produced by Tyler Clang. If you miss Christian you can 0:05:16.080 --> 0:05:19.080 find him on his new pop culture podcast super Context, 0:05:19.360 --> 0:05:21.560 And of course, for more on this and lots of 0:05:21.560 --> 0:05:24.599 other deep topics, visit our home planet, how Stuff Works 0:05:24.680 --> 0:05:36.360 dot com.