o e

e au eu

i ou u

Eccentric. Normal. Concentric.

This is the only simple sound, but four other sounds are derived from
it. The three _a's_ articulated by closing the uvula, give the nasal
_an_. Each family also gives its special nasal sound: _in_ for the
eccentric voice, _on_ for the normal state, _un_ for the concentric. All
other sounds are derived from combinations of these. The mouth cannot
possibly produce more than three families of sounds, and in each family
it is _a_ united with the others that forms the trinity.

The variety of sounds in these three families of vowels arises from the
difference of the opening of the mouth and lips in articulating them.
These different modes of articulation may be rendered more intelligible
by the subjoined diagrams:

_a_ is pronounced with the mouth very wide open, the uvula raised and
the tongue much lowered.

---------------------
O O
---------------------

_e, e, i_ and _in_ are articulated with the lips open and the back part
of the mouth gradually closed.

/
/
/
\
\
\

_a, au, ou_ and _on_ are articulated with the back of the mouth open and
the lips gradually closed.

\
\
\
/
/
/

_e, eu, u_ and _un_ are articulated with the back of the mouth and the
lips uniformly closed.

---------------------
---------------------

The voice takes different names, according to the different sounds in
each family of vowels: the chest-voice, the medium voice and the
head-voice.

These names imply no change in the sort of voice, but a change in the
manner of emission. The head, medium or chest-voice, indicates only
variety in the emission of vowels, and may be applied to the high as
well as the deep and medium voice. Thus the deep voice may produce
sounds in the head-voice, as well as in the medium and chest voices.

The head-voice is produced by lowering the larynx, and at the same time
raising the uvula. In swallowing, the larynx rises by the elevation of
the uvula, without which elevation there can be no head-tones.

_Practical Conclusions._

1. It is highly important to know how to assume either of these voices
at will. The chest-voice is the expression of the sensitive or vital
life, and is the interpreter of all physical emotions. The medium voice
expresses s