When you speak, air rushes from your lungs and makes your vocal cords vibrate, producing the sound of your voice. If you’ve ever plucked a small, thin rubber band, you’ve heard the high-pitched twang it makes when it’s stretched. A thicker rubber band makes a deeper, lower-pitched twang. It’s the same sort of thing with vocal cords.
Before you reach puberty, your larynx is pretty small and your vocal cords are kind of small and thin. That’s why your voice is higher than an adult’s. As you go through puberty, the larynx gets bigger and the vocal cords lengthen and thicken, so your voice gets deeper. As your body adjusts to this changing equipment, your voice may “crack” or “break.” But this process lasts only a few months. Once the larynx is finished growing, your voice won’t make those unpredictable, funny noises anymore.
The larynx (say: LAIR-inks), also known as your voice box, actually gets bigger during puberty. The larynx, located in your throat, is a tube-shaped piece of cartilage — the same stuff your ears and your nose are made from. One of its jobs is to let you talk, sing, hum, yell, laugh, and make all sorts of noises.
When a boy reaches puberty, his body begins making lots of testosterone (say: tes-TOSS-tuh-rone). The testosterone causes his larynx to grow and his vocal cords to get longer and thicker. Vocal cords are thin muscles that stretch across the larynx like rubber bands.