CHAP TEE L V I I 



VOICE AND SPEECH 



THE fundamental tones of the voice are produced by the current of 

 expired air causing the vibration of the vocal cords, two elastic bands 

 contained in a cartilaginous box placed at the top of the windpipe 

 or trachea. This box is called the larynx. The sounds produced 

 here are modified by other parts such as the tongue, teeth, and lips, 

 as will be explained later on. 



Anatomy of the Larynx. 



The cartilages of the larynx are the thyroid, the cricoid, and the two arytenoids. 

 These are the most important for voice production ; they are made of hyaline carti- 



Cornu min. 

 Cornu maj- ... 



Cornu sup. 



.. m. ' Sterno-hyoideus 



- in. Thyro-hyoideus. 



m. Sterno-hyoideus. 

 m. Crico-thyroideus 



Lig. crico-thyr. nied. 



Cart, cricoidea 

 Lig. crico-trachese 



Cart, tracheale 



FIG. 498. The larynx, as seen from the front, showing the cartilages and ligaments. The muscles, with 

 the exception of one crico-thyroid, are cut off short. (Stoerk.) 



lage. Then there are the epiglottis, two cornicular, and two cuneiform cartilages. 

 These are made of yellow fibre-cartilage. 



The thyroid cartilage (fig. 499, 1 to 4) does not form a complete ring around the 

 larynx, but only covers the front portion. It forms the prominence in front of the 



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