vn VOICE 335 



thyroid and thyro-arytenoid muscles. For when the 

 thyro-arytenoid muscles are fully contracted, the thyroid 

 cartilage will be raised, relatively to the cricoid, as far as 

 it can go, and the vocal cords will be rendered relatively 

 lax ; while, when the crico-thyroid muscles are fully 

 contracted, the thjrroid cartilage will be depressed, 

 relatively to the cricoid, as much as possible, and the 

 vocal cords will be made more tense. 



If, while a low note is being sounded, the tip of the 

 finger be placed on the crico-thyroid space (which can 

 be felt, through the skin, beneath the lower edge of the 

 thyroid cartilage), and a high note be then suddenly pro- 

 duced, the crico-thyroid space will be found to be narrowed 

 by the approximation of the front edges of the cricoid and 

 thyroid cartilages. At the same time, however, the whole 

 larynx is, to a slight extent, moved bodily upwards and 

 thrown forwards, and the cricoid has a particularly dis- 

 tinct upward movement ; this movement of the whole 

 larynx must be carefully distinguished from the motion 

 of the thyroid relatively to the cricoid. 



The range of any voice depends upon the difference of 

 tension which can be given to the vocal cords, in these 

 two positions of the thyroid cartilage. Accuracy of 

 singing depends upon the precision with which the singer 

 can voluntarily adjust the contractions of the thyro- 

 arytenoid and crico-thjToid muscles — so as to give his 

 vocal cords the exact tension at which theii" vibration 

 will yield the notes required. 



The quality of a voice — treble, bass, tenor, &c. — on 

 the other hand, depends upon the make of the particular 

 larynx, the primitive length of its vocal cords, their 

 elasticity, the amount of resonance of the surrounding 

 parts, and so on. 



Thus, men have deeper notes than boys and women, 

 because their larynxes are larger and their vocal cords 

 longer — whence, though equally elastic, they vibrate less 

 swiftly. 



