How to Check Gear Box Vibration.

What Your Voice Box Does When You're Nervous or Growing Your vocal folds vibrate over a hundred times per second—and a voice crack isn't a broken voice box. It's your brain and throat momentarily out of sync. Right now, your body is running a delicate coordination between tiny muscles, air pressure, and the length and tension of those folds. When that coordination slips, you get a crack. Research from the National Institutes of Health shows that pitch is controlled by laryngeal muscles adjusting