Vocal Organ.
The organ assumes at birth a form; this form is called the timbre or tone, This tone corresponds to the constitutional form. Under the sway of habit, the form assumes an acquired tone which is called emission. The emissive form corresponds to the habitual tone. Under the sway of emotion the voice is modulated and assumes forms which we will call passional or transitory.
The mouth is normal, concentric and eccentric. [See chart in Delaumosne, page 81.]
From these three types we have succeeded in fixing and classifying forty-eight million phenomena.