It might seem like yesterday that your child was in diapers and crying out for you in the middle of the night. Now, a teen's living in your house. A 13-year-old is going through physical and emotional changes, including vocal changes. While the age of voice changes for children varies, it usually hits when puberty really hits 3.
Age
According to KidsHealth, a child's voice often changes after a big growth spurt, meaning your child suddenly grew a few inches 12. The voice change can happen from ages 11 to 14 1/2, so it's perfectly normal for a 13-year-old to have a deep voice.
Voice Changes
For some teens and preteens, it can seem as though their voice changed changed overnight -- the voice goes from a high, child's voice to a more mature, deeper voice. In other kids, the process is much slower and it your son's voice may change and deepen gradually. In any event, the voice change should be complete within a few months, and the embarrassing voice cracking will be a thing of the past.
Boys and Girls
While the voice changing and deepening is certainly more dramatic in boys, young girls usually go through voice changes as well 2. When a girl hits the teen years, her voice will also deepen a bit and become more adultlike. Generally, however, girls don't have the voice cracking that characterizes a boy's voice changing 2. Girls voices tend to deepen more smoothly and gradually and not nearly as much as a males.
Related Changes
Around the same time a boy's voice starts to change, something else happens. According to PBS Kids, explains that many boys will start to develop a more prominent Adam's apple around the same time as a voice change 3. Girls might also develop a bit of an Adam's apple, but it will be far less noticeable than on a male. It does not matter whether an Adam's apple is prominent or small, much in the same way that it makes no functional difference whether a person has blue or brown eyes. It's just the way different people develop.