Did some research....
[b]Puberphonia[/b] (mutational falsetto): "failure to change from the higher pitched voice of preadolescence to the lower pitched voice of adolescence and adulthood" (Aronson). The sound of the voice is usually high-pitched, "weak, thin, breathy, hoarse, and monopitched, giving the overall impression of immaturity, effeminacy and passiveness" (Aronson). Sometimes there has been resistance to 'growing up' for some reason; even when this is overcome, the person may not have learned to use the muscles differently with physical maturation, in which case this must be taught. Once arrest of physical growth has been ruled out, and the commitment of the person to make the transition to adult voice has been established, the change can be rapid. Emotional resistance to the change is rare, and the focus is usually on physical re-education.