The whistle register is the highest register of the human voice, lying above the modal register and falsetto register. This register has a specific physiological production that is different from the other registers and is so called because the timbre of the notes that are produced from this register is similar to that of a whistle.

The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice frequency is specifically a part of human sound production in which the vocal folds are the primary sound source.