Voices

I took my oldest son to the doctor last month for his Scout physical. He's 5'9" now, three inches taller than me. The growth that keeps taking me by surprise is invisible, though: his larynx is bigger than mine.

Your larynx sits right on top of your trachea. Its primary purpose is to protect your airway, but as a lovely bonus God designed the system so we can also use it to talk and laugh and sing and yodel. (Well, maybe God didn't intend that last one. Was there yodeling before the Fall? I am skeptical, personally.)

When you want to say something you bring your vocal folds together and push air through them. They pulse rapidly, creating a buzzing tone that you shape with your throat and tongue and teeth and lips. (And velum. The velum is the most unappreciated articulator, even though it is largely responsible for keeping you from sounding whiny and nasal.)

The size of your larynx plays a key role in the pitch of your voice, because more mass in the vocal folds = fewer pulses per second. An average man's vocal folds might vibrate 120 times per second, meaning his voice will fall about an octave below middle C. An average woman's vocal folds will vibrate about twice that fast, giving her a voice roughly an octave higher. My voice is pitched a smidge higher than usual, at about the E above middle C. (You can hear me talking at the beginning of the video embedded here if you're curious. I don't walk around talking like Glinda the Good or anything.)

So I am used to my son's big pre-man feet, and I accept that he's taller than me forevermore. But his voice keeps throwing me for a loop. I keep turning around and thinking, "Who's that MAN in my house? Why is there a MAN in here?" And then I think, "...whoa, that's my son with that big manly voice."

Tonight in the van I was trying to estimate his fundamental frequency (I bet you wish your mom was a speech pathologist too!), humming along as he spoke. I'd put it at about the G below middle C -- not so terribly low, but unmistakably different from his brothers' voices.

I know it will just keep dropping as he matures, since one of the effects of androgens is to enlarge the larynx. You can measure growth with pencil marks on the wall, sure, but you can also measure it with a descending scale on the piano.

Tonight I was imagining a future in which all of my boys will go tripping down that scale, and it left me a little wistful. I'm going to hold onto my memories of our drive tonight -- of my firstborn and my baby talking together, her chirping soprano interweaving with his beginner baritone.