Why do boys' voices break?

Question: Why do boys' voices break?

Answer: Commonly known as the "teste pops" the "breaking" of the male voice is not the violent event that the name suggests. Boys’ voices "break" when they reach puberty and a spectacular growth spurt begins as a result of the increased production of testosterone. During this time, usually between the ages of 10 and 14 years old, the voice box grows, the pitch of the voice lowers and the resonance of the voice becomes that of an adult male. The noticeable physical change to the voice is that the Adam’s apple becomes more pointy and prominent in the throat as the cartilage grows. This allows vocal cords to lengthen, such that the vocal folds double in length over this time, with a male adult bass having vocal cords up to 23 millimetres long. The voice box also lowers in the throat as the boy’s height increases. All of these changes can happen quickly, over months rather than years.

Like the gangly teenager struggling to control quickly growing limbs, so too the young man has to get control of a much larger pair of vocal cords and a much larger voice box. Voicing is a complex muscular activity, requiring 22 muscles in and around the voice box alone to co-ordinate their movement in 1/10 of a second. Voicing happens when the vocal cords are drawn across the airway and air pressure from the lungs is produced to make the edges of the vocal cords flutter. When the vocal cords double in size, not only do you need more air pressure to make them flutter, the movement of the muscles that control the position of the vocal cords must change, all at the same time. Occasionally, the voice instructions subconsciously don’t produce the sound expected, and a crack results. It’s the equivalent of learning to drive in a mini, then suddenly having to drive a truck. It takes a while to adjust to controlling a bigger instrument.

Answer by Cate Madill, PhD in speech pathology,  University of Sydney

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