HYGIENE OP THE VOCAL ORGANS 491 



Ai-ticulate speech is the result of voluntary changes in 

 these resonating cavities, and the organs most concerned in 

 producing the changes are the lips, tongue, and teeth. 



Vowels are oi)en-mouth sounds, with corresponding 

 changes in the lip and cheek positions. Consonants are 

 closed-mouth sounds, and tongue, lips, teeth, and cheeks 

 aid in their production. Harshness, softness, etc., are due 

 to differences in the quality of the vocal cord vibrations 

 and the character of the resonating cavities 



In a child the resonating cavities and larynx are smaller 

 than in adults. At about thirteen to fifteen years of age 

 the larynx widens rapidly and the cords lengthen. The 

 result is a deepening of tone and a change of voice. 



The vibrations of the cords are under voluntary control, 

 and it is possible by practice to control these vibrations 

 and the shape of the resonators so as to improve greatly 

 the clearness and quality of the voice. 



Hygiene of the Vocal Organs. 



Since the voice is under voluntary control it is important 

 that children be taught to control it properly. This teach- 

 mg must be mainly by example, and the best training is 

 secured by giving the child good examples to follow. Sing- 

 ing lessons are also valuable in teaching by exercise the 

 proper control of the vocal muscles, even though the child 

 never become a singer. Exercise which develops the lung 

 capacity also increases the volume and resonance of the 

 voice. 



If the lining of the larynx becomes inflamed through 

 colds or irritation the vocal sounds are at once affected. 

 Similarly, inflammation of the walls of the resonators or air 



