On the Articulation of the Human Voice. 155 
some of the effects are lost. The quantity of air which passes 
through the trumpet averages about 14 cubic inches for a syllable, 
but varies greatly in different syllables. 
Action of the Logograph. 
The simplest sounds which can be uttered are vowel sounds. 
They are made by the expulsion of air from the mouth when 
the larynx and other organs of articulation are in certain states 
and conformations. 
When the instrument is adjusted to exhibit them they appear 
in the form shown in the Diagrams on page 172. 
The term consonant indicates some defined manner of com- 
mencing or ending a syllable. 
A sonorous* syllable may be of four different constructions, viz. : 
1. A vowel sound alone. 
. A vowel sound commenced by consonant action. 
A. vowel sound terminated by consonant action. 
. A vowel sound commenced and terminated by consonant 
action. 
bo 
um 
When the Logograph is adjusted to show the consonant action 
the following effects arise. 
If the sound be is made, the diagram produced is 
Sa 
and if it is preceded by breathing or any vowel sound, it becomes 
ecm ee 
2 
In this diagram, 1 shows the preparatory action of closing the 
lips; 2 is a pause, during which pneumatic pressure accumulates 
within the mouth; 3 is the consonant action, in this case positive, 
made by opening the lips suddenly; 4 is the discharge of air 
accompanied by the vowel sound; and the remainder of the figure 
shows the manner in which the pneumatic pressure subsides to 
zero. 
* The word sonorous is used because it will be seen that there are other syllabic actions 
besides those accompanied by vowel sounds. 
bo 
Scien. Proc. R.D.S., Vou. 1, Pr. m1. M 
