Patterns in Particles: Talking Means Moving Air!
Read The First Paragraph Aloud:
You’re doing it right now. As you read these words aloud you’re using
language. In the simplest terms, you are at this very moment watching light jump out of your screen. Now that it’s hitting your eye, the differences in light are being interpreted as the black symbols against a white background. Your brain is taking these squiggles and swoops and, using your memories and experiences, is passing signals to the muscles in your head to make the words you are now saying.
Language: A Powerful Tool
If that felt easier than it sounds, you’ve come to appreciate
language a little bit more. Language, as you can see, is a most powerful tool. It allows me to put thoughts in your head and words on your lips. If people in Australia read this, my thoughts will be transferred all the way there. What’s more, if my grandchildren read this my thoughts will travel through time! Humans love to connect– we love to exchange thoughts and feelings, and language is a perfect way to do that! Why’s That?
It’s because of the very nature of language itself; language was
designed by humans to be that perfect tool. As we changed and evolved in our distant past, we humans found lots of fun new ways to communicate. We learned that we could change the shape of our bodies, move our limbs and faces to
communicate to our fellow cave-dwellers how we were feeling, what we were planning, or who we were in our society. That’s a lot of information already, and what we wanted to say kept evolving along with us. Over the next several thousand years we
homo sapiens found newer, more complicated ways of expressing newer, more complicated ideas. The technique you used to read the first paragraph aloud is a mix of reading and my personal favorite:
speech.
Gimme an ‘A’!
Imagine you’re at a football game. The players leave the field and in come the cheerleaders to stir up the crowd. As the cheerleaders are chanting, they’re using
speech to transmit what their brains are thinking (in this case, ‘A’!) out into the air around them. If they’re loud enough, the air next to your ear will vibrate the message into your brain, and voila! When you hear "ay" and think ‘A’, you’re now thinking the same thing as the cheerleaders. You successfully used your language code to receive their thought!
That might not
technically be what you’d call a psychic power, but it’s pretty cool that our minds and bodies are perfectly equipped to beam our thoughts to each other that way. In fact, the sounds that your ears hear most easily just happen to be the frequencies that human vocal cords produce. Pretty handy back in the day when hearing another hunter’s warning meant the difference between staying alive and becoming dinner. But how does it all work? Vibrating air? You betcha.
Pressure Process: How Human Speech Works
When your brain decides to transmit a message using
speech, the muscles in your body use the air in your lungs to vibrate the ‘vocal cords’ in your throat. The muscles in your tongue, mouth and lips, according to the directions they get from your brain, change the sound. When you hear sounds like these that are familiar to you, you call them “words.” Not so complicated, right? Except that those sculpted sounds are part of an extremely intricate system, relying on many particular characteristics that make up the “code.” Thinking of languages as codes is one way of trying to understand how we use language as a tool. The English language, for example, is the code that English speakers use to beam their thoughts and ideas back and forth to anyone else who knows the code. Ever overheard a conversation in a language you don’t speak? You can’t receive the thoughts and ideas if you don’t know the code!
Physics Is Your Friend: Acoustics! oustics! oustics!
The ol’-vibrating-air-trick only works because the air around us vibrates predictably (thanks, physics!). That means that the human body can vibrate the vocal cords at a certain speed and expect the same sound again and again. The vocal cords move towards and away from each other faster than the eye can see, buzzing the air in your windpipe at the same speeds. If you could zoom-in on the air molecules as they vibrated and slow them way down, they’d look something like this:
If you look carefully at the “air particles” (I think the left-most column of them is easiest to track) you’ll notice that they don’t just shoot off into the distance (toward someone's ear). In reality, they only move a tiny distance. That means that a “sound wave” isn’t air moving towards you like a breeze - it’s more like ripples in a pond. As you can see in the animation above, the molecules stretch apart and clump together, and since we’re talking about the fluid air, how clumped they are is a change in air
pressure. So sound, then, is the pulsing changes in air pressure we cause with our vocal cords. How fast the molecules are bouncing around is called the frequency of the sound wave, which to our ears sounds like how “high” or “low” the pitch of the sound is. Also, the (really tiny) distance the molecules actually move reflects how much energy made them move in the first place. The more energy that created the sound, the farther the molecules ‘bounce’, the louder it is. In fact, you might have a stereo that measures volume in dB (decibels). The decibel is a measurement of how much power was put into producing the sound you're hearing compared to the minimum amount of power needed to hear
anything. Still with me?
Speech In A Nutshell
What Does It All Mean?
When two humans want to transmit ideas, they use a special code they both know called a
language. Languages are systems of symbols that “create the same picture” in the minds of two people who use the same symbols, that is to say, speak the same language. Using these symbols, members of our species can transmit anything from simple ideas like “This water’s hot!” and “I need food” to incredibly complex feelings such as “I love you” and “It’s raining cats and dogs.”
Languages are codes made up of symbols that are expressed, at least some of the time, by pulses in air pressure produced by using the vocal cords. Our brains interpret these pulses of air, which we call “words”, and that’s
speech.
Next time, I’ll look into where language happens
inside the body. Your miraculous brain has a shockingly sophisticated system that creates speech, allows you to read, and taught you your first word. It’s a system we don’t fully understand yet, but what we do know shows how incredible and versatile our wrinkly gray supercomputers can be! Part II – “Language Machines: Brains are the Engines of Expression!” coming soon!
