The vocal change in boys usually occurs around the age of 11-14 years, although the time of vocal change may vary from boy to boy due to the different timing of puberty initiation. Usually, the vocal change period means that the boy has entered puberty, and the initial period of puberty is mainly characterized by the change of testicular volume, which will gradually increase, usually with a testicular volume >4mL, which means that the boy has entered the puberty initiation period, and gradually the vocal change will occur. Usually boys will have puberty initiation after nine weeks of age, and with the increase in testicular size and androgen secretion, they will experience voice change and then the growth of a small beard. In adolescence boys will get a physical leap, at this time will also be a significant growth in height, is the prime period of height growth, pay attention to ensure adequate sleep and balanced nutrition.