THE VOICE 325 



two vocal cords (Fig 1 . 73, F), which pursue a similar direction 

 to the false cords namely, from before backward. They are 

 composed of a highly elastic, though strong tissue, and are 

 covered with a thin, tightly fitting layer of mucous membrane. 

 Their edges are smooth and sharply defined, and when they 

 meet, as they do in the formation of sounds, they exactly 

 match each other. 



8. Between the true and false vocal cords is a depression on 

 each side, which is termed the ventricle of the larynx (Fig. 

 73, D). The integrity of these two cords, and their free vibra- 

 tion, are essential to the formation of the tones and the modu- 

 lation of the natural voice. This is shown by the fact that, if 

 one or both of these cords are injured or become diseased, 

 voice and speech are weakened; or when the mucous mem- 

 brane covering them becomes thickened, in consequence of a 

 cold, the vocal sounds are rendered husky and indistinct. 

 When an opening is made in the throat below the cords as 

 not infrequently occurs in consequence of an attempt to com- 

 mit suicide voice is impossible except when the opening is 

 closed by external pressure. 



9. The interval or space between the true cords of the voice is 

 constantly varying, not only when their vocal function is in ex- 

 ercise, but also during the act 

 of respiration. Every time 

 the lungs are inflated, the 

 space increases to make wide 

 the entrance for the air, and 

 diminishes slightly during ex- 

 piration. So that these little 

 cords move genly to and fro 

 in rhythm with the expansion 

 and contraction of the chest 

 in breathing. These move- 



FIO. 74. A VIEW or THE VOCAL CORDS BY ments and others may be 



MEANS 'or THE LARYNGOSCOPE . , , 



seen to take place, it a small 



8. Where is the ventricle of the larynx? The essentials to the formation of the tones 

 and modulation of the voice ? 



^ Variation in the interval between the true cords of the voice ? Experiment with the 

 mirror. 



