ANDY'S ANSWER: Most Boys have a short period of time where their voice cracks occasionally. The voice change is actually because your larynx is growing and your vocal cords are getting thicker and longer. The more your larynx and vocal cords grow, the deeper your voice will end up being. The cracking usually just happens for a month or two while you are getting used to talking with a changing voice box, even though your voice can continue to deepen into your twenties.