A 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. 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.A 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. 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. 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.

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