
Castrati are first documented in Italian church records from the 1550s. Historically, a strategy for avoiding the shift altogether was castration. In German-speaking countries, however, the alto parts are also sung by boys. The British cathedral choir ideal remains based on boy sopranos (or trebles), with the alto part executed by adult countertenors. Unchanged voices were in high demand for church choirs, which historically excluded women. The composer Joseph Haydn was known for typically singing parts in high pitches throughout his 17th year. Historical changes in the average age of puberty have had profound effects on the composing of music for children's voices. Due to the significant drop in pitch to the vocal range, people may unintentionally speak in head voice or even strain their voices using pitches which were previously chest voice, the lowest part of the modal voice register. Occasionally, voice change is accompanied by unsteadiness of vocalization in the early stages of untrained voices. Cavities in the sinuses, the nose, and the back of the throat grow bigger, thus creating more space within the head to allow the voice to resonate. Along with the larynx, the vocal folds (vocal cords) grow significantly longer and thicker. This growth is far more prominent in males than in females and is more easily perceived. Under the influence of sex hormones, the voice box, or larynx, grows in both sexes. It usually happens months or years before the development of significant facial hair. Adult pitch is reached 2–3 years later but the voice does not stabilize until the early years of adulthood. Most of the voice change begins around puberty.

An instance of a voice crack (when associated with puberty) lasts for only a moment and generally occurs less frequently as a person grows into maturity.

This may be caused by singing or talking at a pitch outside the person's natural vocal range, stress, fatigue, emotional tension, or the physical changes associated with puberty. Ī similar effect is a " voice crack", during which a person's voice suddenly and unintentionally enters a higher register (usually falsetto) for a brief period of time. Before puberty, both sexes have roughly similar vocal pitch, but during puberty the male voice typically deepens an octave, while the female voice usually deepens only by a few tones. For transitions between different vocal registers in singing, see Voice break.Ī voice change or voice mutation, sometimes referred to as a voice break or voice crack, commonly refers to the deepening of the voice of men as they reach puberty.
