What Causes a Boy's Voice to "Break" or Change at the Onset

Question

What causes a boy's voice to "break" or change at the onset of puberty?
A) Rapid growth of the throat region stretches the vocal cords.
B) Testosterone causes the vocal cords to thicken.
C) Testosterone closes the glottis permanently.
D) Testosterone enlarges the thyroid cartilage (Adam's apple).

Accepted Answer

At the onset of puberty, the testes begin to produce hormones, including testosterone, which causes the larynx (voice box) to grow and the vocal cords to thicken. This results in a deeper, more mature voice.