His Voice is Changing

If you were a Brady Bunch fan, you may recall the episode where Peter’s voice changes. In case you haven’t seen it, the Brady kids are getting their big break as a singing group, and Peter’s voice starts cracking just before their recording gig. So while the rest of the family are harmonizing beautifully, poor Peter ruins the song.

What the Brady Bunch episode didn’t explain is why boys’ voices change during puberty. As with many of the changes that occur at this awkward time in a boy’s life, rising levels of testosterone are the culprit. The increase in this hormone causes changes all over the body, including in the larynx, or voice box.

The larynx is located in the throat, at the top of the trachea (also called the wind pipe) and it contains the vocal cords. These two muscles tighten and relax to change how air passes through the larynx. When you raise or lower the pitch of your voice, it is the tightness of the vocal cords that causes the pitch to change. So, changes in the larynx or vocal cords affect your voice.

During puberty, testosterone causes a boy’s larynx to get bigger. The vocal cords also lengthen and thicken in response to testosterone—in fact they can increase in length more than 60% in boys during puberty.

Just as the shortest strings on a harp or piano make the highest sounds, the short vocal cords of children produce voices that are high in pitch. The longer cords of adult males produce lower pitched voices.

As the larynx and vocal cords are going through this growth phase, the changes can cause the “Peter Brady effect.” Sometimes the change of voice seems abrupt in boys—over only a few weeks or months, the voice begins to crack and then becomes deeper and more resonant.

As girls go through puberty, their vocal cords also lengthen, but they grow a more modest 25%, so their voice changes are not as noticeable.

If a boy does not go through puberty because of a deficiency of testosterone, his voice will remain high. In fact, in 16th-, 17th- and 18th-century Italy, 7- to 9-year-old boys with a talent for singing operatic or religious music were sometimes castrated to preserve the high pitch into adulthood. (Testosterone is produced in the testes, so if you remove them, a boy won’t go through puberty.)

In contrast, if adult women take male hormones as part of a medical treatment, their voices will become irreversibly lower in pitch.

There’s nothing a boy can do to prevent his voice from cracking as he goes through puberty. Though it can be embarrassing, boys should take comfort in knowing this happens to all teenage boys and it will pass soon enough.

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