voice change period; puberty (age of voice change)
Refers to the stage in adolescence when the voice deepens, especially in boys. Often used in contexts of singing or voice training.
彼は変声期で声が低くなった。
His voice deepened during the voice change period.
Children in the voice change period should avoid forcing high notes.
Compound of 変 (hen, 'change'), 声 (sei, 'voice'), and 期 (ki, 'period'). The term directly describes the period of voice change during puberty.