In an analysis of the physical components necessary for sound production – power source, oscillator, resonator – breath occupies the most active place in human vocal production: it is the energy impulse that excites the vibration in the vocal folds and the resulting resonance in the body – starting, continuing, and stopping it. Because of the living and therefore infinitely changeable quality of the particular actions and structures that are responsible for this sound vibration, the way in which the human body breathes impacts the voice a great deal, much as the hands of a good pianist and a beginner create different sounds with the same instrument. Breathing, then, makes an essential difference in quality of vocal production. By quality I refer not only to timbre, but to the entire range of use of the voice.
Voice is an action. It has no location in the body except when it is in action, sounding. The essential physical structures – diaphragm, intercostal, abdominal and back muscles; larynx; articulators; body form and cavities – are in themselves virtually mute until with a particular use of the breath and vocal folds they all inter-relate as power source, oscillator, and resonator to create sound. It is for optimal functioning of the breath energy, as power source, that I have searched.
From Riley Dog