Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff,
Speaker 1: I'm Lauren voc Obam, and today's episode is another brain
Speaker 1: Stuff classic from our erstwhile host, Christian Sager. Our question
Speaker 1: for the day, why do men tend to have deeper
Speaker 1: voices than women? Hello, brain Stuff, I'm Christian Saga, and
Speaker 1: today we're going to talk about the human voice. You
Speaker 1: might have noticed that if you're talking to a group
Speaker 1: of five year old boys and girls, let's say you're
Speaker 1: asking them for advice about your investment portfolio, there's not
Speaker 1: a big difference between the pitch of the girl's voices
Speaker 1: and the pitch of the boys voices. Yet if you
Speaker 1: talk to a group of thirty five year old men
Speaker 1: and women, you notice that the men's voices are on
Speaker 1: average a good bit deeper than the women's voices. So
Speaker 1: why is that and how does it happen? Well, first off,
Speaker 1: let's acknowledge that everyone is a special and unique butterfly,
Speaker 1: and there's no rule about how men and women's voices
Speaker 1: should sound. But on average, adult men's voices have what's
Speaker 1: known as a lower fundamental frequency than adult women's voices.
Speaker 1: The fundamental frequency is simply the scientific term for how
Speaker 1: high or low a person's natural speaking voice sounds. Sound
Speaker 1: frequency is measured in hurts, which is a measure of
Speaker 1: how many times something happens in a second. So a
Speaker 1: sound wave that vibrates a hundred times per second produces
Speaker 1: a tone of a hundred hurts. The more cycles per second,
Speaker 1: the higher the pitch. According to the National Center for
Speaker 1: Voice and Speech, babies usually cry at a frequency of
Speaker 1: around five hundred hurts. Children have speaking frequencies in the
Speaker 1: range of two hundred and fifty to four hundred hurts
Speaker 1: by the time of adulthood. However, men have an average
Speaker 1: fundamental frequency of about one hundred and twenty five hurts
Speaker 1: and women about two hundred hurts. What happened here? What?
Speaker 1: Why the big difference? Okay, to understand why men's voices
Speaker 1: end up lower than women's voices, we need to look
Speaker 1: at how the body produces sounds. So let's take a
Speaker 1: magical journey to the inside of your neck. Leading from
Speaker 1: your lungs to the cavity behind your mouth and nose
Speaker 1: is a pipeline called the tray chia. You use it
Speaker 1: to breathe. At the top of the trachea is a
Speaker 1: hollow organ called the larynx, or in common parlance, the
Speaker 1: voice box. The larynx is amazing. For example, when you
Speaker 1: swallow food, it is a part of the larynx called
Speaker 1: the epiglottis that closes off your tray chia and keeps
Speaker 1: you from getting gummy bears in your lungs. The larynx
Speaker 1: is also what allows us to make sound for talking
Speaker 1: or singing. To do this, you use your lungs to
Speaker 1: push a column of air through the larynx while using
Speaker 1: your laryngeal muscles to press together a pair of membranes
Speaker 1: called the vocal folds, or more commonly, your vocal chords.
Speaker 1: When you close the vocal folds like this, the air
Speaker 1: you push out through them makes them vibrate, and this
Speaker 1: vibration leads to sound. So the next time you're just
Speaker 1: shrieking and shrieking until the cashier finally accepts your expired coupon,
Speaker 1: thank your larynx. There are several factors that can all
Speaker 1: have some effect on the fundamental frequency of a person's voice,
Speaker 1: like the size of the larynx and the differential development
Speaker 1: of facial bones and muscles. But the most important factor
Speaker 1: to talk about is the length of the vocal folds.
Speaker 1: If you pluck a string, the length of the string
Speaker 1: affects the frequency of the note that plays. Think about
Speaker 1: a guitar. When you press a string down to a
Speaker 1: higher fret. On a guitar, you shorten the length of
Speaker 1: the part of the string that vibrates when you pluck it,
Speaker 1: and this produces a higher note. The same thing happens
Speaker 1: inside your larynx. The longer the vocal fold, the lower
Speaker 1: the note. During puberty, both boys and girls experience growth
Speaker 1: of the vocal folds, leading to lower voices, but the
Speaker 1: male hormone testosserone, which is released by the testicles during puberty,
Speaker 1: typically causes boys vocal folds to grow longer and thicker
Speaker 1: than girls. On average, adult women have vocal folds somewhere
Speaker 1: around ten millimeters long, while adult men have vocal folds
Speaker 1: in the neighborhood of sixteen millimeters. Consequently, women are up
Speaker 1: there on the upper frets, soloing into oblivion like a
Speaker 1: high school kid who just learned how to play eruption
Speaker 1: by Van Halen, and men are letting the open strings
Speaker 1: ring like the intro of nothing else matters by Metallica.
Speaker 1: Now here's some bonus information for you. Everyone knows what
Speaker 1: happens when you inhale some helium from a party balloon
Speaker 1: or you know, straight from an industrial helium transport truck.
Speaker 1: Your voice pitch gets higher. This is because helium is
Speaker 1: less dense than air. But did you know you can
Speaker 1: reverse the effect and give yourself a deep, booming bridge
Speaker 1: troll voice by breathing a gas with a higher density
Speaker 1: than your air, like zenon or sulfur hexafloor a ride.
Speaker 1: But remember, your body needs air to live, and breathing
Speaker 1: anything other than air can be dangerous, so don't try
Speaker 1: this at home. Today's episodes written by Joe McCormick and
Speaker 1: produced by Tyler Clang. If you miss Christian you can
Speaker 1: find him on his new pop culture podcast super Context,
Speaker 1: And of course, for more on this and lots of
Speaker 1: other deep topics, visit our home planet, how Stuff Works
Speaker 1: dot com.