The process of phonation is the first complex motor act that heralds the infant’s entry to the world and is not uncommonly the last an individual achieves at the end of human life. The nature of the phonation produced changes significantly throughout life. The rapid transient changes conforming to the linguistic and communicative needs of the individual occur against a backcloth of phonatory function that alters slowly throughout our speaking lives. Most of these latter changes occur so gradually that they are hardly noticed by either speaker or listener. A few, however, have a dramatic impact, such as the shift from a boy’s voice to the mature male pattern of phonation.