[...]form. A register consists of a series of tones produced by the same mechanism. -Emil Behnke in Voice, Song, and Speech. G.Edward Stubbs, in commenting upon the above definition, says: By mechanism is meant the action of the larynx which produces different sets of vibrations, and by register is meant the range of voice confined to a given set of vibrations. In passing the voice from one register to ather, the larynx changes its mechanism and calls into play a different form of vibration. [...].