1. A method of establishing a vocal demeanor for an application having a speech interface that presents speech content according to the vocal demeanor, the method comprising: selecting, based on at least one attribute of a user, a particular voice family, wherein the particular voice family identifies a particular person's voice by describing an overall nature and timbre of the particular person's voice in specific terms; and selecting the vocal demeanor for the application to use the particular voice family that identifies the particular person's voice.