PHONATION; ARTICULATE SPEECH. 



aperture of the glottis during this time being elliptic in shape and 

 relatively wide (Fig. 268). In the production of notes due to 

 vibrations lying between 240 and 512 vibrations per second, the 

 anterior fibers of the crico-thyroid muscle relax and the thyro-ary- 

 tenoid muscle comes into play; by its action the vocal bands are 

 more closely approximated and the vocal aperture reduced to a 

 linear slit. In the high-pitched notes emitted by soprano singers the 

 vocal bands are so closely applied to each other that only a very 

 small portion in front, bounding a small oval aperture, is capable 

 of vibrating (Fig. 269). The difference in the pitch of the voice 

 in men and women is due largely to the 

 greater size and development of the vocal 

 bands in the former than in the latter. 



The quality of the voice, the timbre or 

 color, depends on the jorm combined with 

 the intensity and pitch of the vibration. 

 As with sounds produced by music in- 

 struments, the primary or fundamental 

 vibration of the vocal band is compli- 

 cated by the superposition of secondary 

 or partial vibrations (overtones). The 

 form of the vibration will therefore be 

 a resultant of the blending of a number 

 of different vibrations. The quality of 

 the sound produced in the larynx is, 

 however, modified by the resonance of 

 the mouth and nasal cavities; certain of 

 the overtones being reinforced by changes 

 in the shape of the mouth cavity more 

 especially, thus giving to the voice a 

 somewhat different quality. 



The Varieties of " Voice. The 

 region of the music scale, comprising all 

 vibrations between 32 and 2048 per 

 second, with which laryngeal sounds are in accord will vary in the two 

 sexes and in different individuals of the same sex. It is customary 

 to classify voices, especially those of singers, into bass, baritone, tenor, 

 contralto, mezzo-soprano, and soprano, in accordance with the regions 

 of the music scale with which they correspond. Thus the succession 

 of notes characteristic of the bass voice vary in pitch from F, fa', to 

 C', do 3 , or from 87 to 256 vibrations per second; those of the baritone 

 from A, la, to F', fa s , or from 106 to 341 vibrations per second; 

 those of the tenor from C, do 2 , to a', Ia 3 , or from 128 to 435 vibrations 

 per second; those of the contralto from e, mi 2 , to C", do 4 , or from 160 

 to 512 vibrations per second; those of the mezzo-soprano from g, so! 2 , 



FIG. 269. GLOTTIS SEEN 

 WITD THE LARYNGO- 

 SCOPE DURING THE EMIS- 

 SION or HIGH-PITCHED 

 SOUNDS, i, 2. Base of 

 the tongue. 3, 4. Epiglot- 

 tis. 5, 6. Pharynx. 7. 

 Afytenoid cartilages. 8. 

 Opening between the true 

 vocal cords. 9. Aryteno- 

 epiglottidean folds. 10. 

 Cartilage of Santorini. 1 1 . 

 Cuneiform cartilage. 12. 

 Superior vocal cords. 13. 

 Inferior vocal cords. (Le 

 Bon.) 



