Is your son wondering why his voice is cracking and what it all means? Find out why his voice is changing and how it relates to puberty and growth.
Puberty and Voice Changes
Our voice is produced when air is forcibly moved through our throat and vocal cords. Our mouth and tongue play a part in forming words, but it is our pair of vocal cords in the throat that influences how deep or how high the tone of our voice is.
These vocal chords, also know as vocal folds, are dual strips of cartilage and other tissues in the voice box (also called the larynx). The vocal folds vibrate to produce the basic sounds that make up our voices. We modify these sounds with our mouths to make words. The longer and thicker the vocal chords the lower pitched the sounds are. When we are born, boys’ and girls’ vocal folds are of similar lengths, measuring about 2 millimeters long, but they continue to grow as the child grows. Girl's vocal folds grow 0.4 mm in length each year, but boy's vocal folds grow 0.7 mm in length for the same time period – almost twice as much. This growth eventually slows down, leaving girls with a maximum vocal fold length of 10 mm and boys with a length of 16 mm. A longer vocal fold means a deeper voice, which is why males tend to have a deeper voice than girls.
These changes in the larynx are all related to the increasing amounts of testosterone in boys during puberty. The increase in testosterone leads to a lengthening of the cartilage of the larynx, the increase in the length of the vocal folds but also a thickening of the vocal folds. Thicker vocal folds lead to a change in the tone and the timbre of the voice – timbre being the quality or “color” of the voice. So when your son's voice cracks, blame it on testosterone and the growing pains of the vocal cords!
Voice Changes and Other Changes In Puberty
Voice changes do not happen in a vacuum. Because the voice changes due to increasing testosterone, and testosterone is causing other changes during puberty, voice changes are bound to be related to other events in the body.
One of the things to note is that voice changes occur during a certain point during the overall changes of puberty. Studies have consistently shown that voice changes happen when boys are between Tanner Stages 3 and 4. The Tanner Stages describe the physical changes in a boy's genitalia during puberty. Your doctor assesses your son's Tanner Stage, so feel free to ask where your son is at – puberty wise – after his next checkup. It may give you an indication if a voice change is on the horizon.
More interestingly, voice changes can be related to your son's height. When your son's voice begins to change, this often marks the beginning of his “growth spurt.” This growth spurt is a time during adolescence where height increases rapidly during adolescence. Once your son's voice stops changing rapidly, his growth spurt has started to decrease. This is not a quick process as growth spurts during the teen years can last two to three years.
Puberty, with its voice changes along with other developments, can be a stressful time for teens, but understanding more about the process can help everyone cope with the situation. If he is concerned about how his voice sounds, you can reassure your son that the squeaks and changes are normal growing pains and that they won't last forever. The good news is that when his voice changes, he'll be getting the growth spurt he has been wishing for!
Haag, U and Taranger, J. Maturation indicators and the pubertal growth spurt. American Journal of Orthodontics October 1982; 82(4):299-309.
Harries, M, Hawkins, S, Hackinga, J, and Hughes, I. Changes in the male voice at puberty: vocal fold length and its relationship to the fundamental frequency of the voice. The Journal of Laryngology & Otology 1998, 112:451-454.
Harries, MLL, Walker, JM, Williams, DM, Hawkins, S, and Hughes IA. Changes in the Male Voice at Puberty. Archives of Disease in Childhood 1997;77:445–447.
Voice Changes Throughout Life. National Center for Voice and Speech. August 22, 2009. http://www.ncvs.org/ncvs/tutorials/voiceprod/tutorial/changes.html