Inspiration should always be followed by a suspensive silence; otherwise the lungs, agitated by the act of inspiration, perform the expiration badly.

Logical Respiration.

Logical respiration constitutes the respiration itself.  Suspension expresses reticence, disquietude.  Inspiration is an element of dissimulation, concentration, pain.  Hence, we have normal, oppressive, spasmodic, superior, sibilant, rattling, intermittent, crackling, and hiccoughing respiration.

Expiration is an element of trust, expansion, confidence and tenderness.  If the expression contains both pain and love, the inspiration and expiration will both be noisy; but the one or the other will predominate according as pain predominates over love, or vice versa.

Passional Respiration.

The source of passional respiration lies in the agitation of the heart.  The effect of respiration is most powerful, for the slighter and more imperceptible the phenomena are, the more effect they have upon the auditors.

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.

Definition of the Voice.

The voice is the essential element in singing.  It is based upon sound. 
This is based upon three agents: 

The projective agent, or the lungs.

The vibrative agent, or the larnyx.

The reverberative agent, or the mouth.

Each of these agents acts in different ways, nine acts resulting therefrom, which we will call products of phonetic acts.

The projective agent in its special activities engenders

    Intensities,
    Shades,
    Respirations.

The vibrative agent in its special activities engenders

    Prolations,
    Pathetic effects,
    Registers.

The reverberative agent in its special activities engenders

    Emissions,
    Articulations,
    Vowels.

To recapitulate, the phonetic agents give us nine products; but, when studied from the vocal point of view, these products become as many elements and must be examined from the triple point of view of preparatory, practical and transcendant studies.  We must, therefore, know first the general definition of these elements, their cause and their theoretical history, which constitutes phonology or the preparatory study of the voice.