CHAPTER XVI. 



Voice and speech. Organ of voice ; larynx, cavity of the larynx, 

 glottis, vocal cords ; the larynx at different ages and in different sexes. 

 Physiology of the larynx; mechanism of the voice; opinions as to the 

 formation of the voice. Galen, Fabricins Acquapendente, Dodart, 

 Ferrein, Biot, Milller, Savart, Masson, and Longet. Theories founded 

 071 laryngoscopic observations. Formation of sounds in whistling. 

 Voice ; speaking voice, mechanism of articulate sounds, vowels ^ con- 

 sonants, timbre of the vowels; the tongne as an organ of pronunciation^ 

 Singing; chest voice, falsetto voice, mixed voice; different theories on the 

 formation of the falsetto : Milller, M. Segond, M. Longet, M. Fournie, 

 M. Bataille, M. Mandl. Timbres of the voice: high pitch, grave pitch. 

 Compass of voices : bass, baritone, tenor, contralto, mezzo-soprano, 

 soprano. Ventriloquy. 



The larynx. The organ of the voice is a sort of a cartilagin- 

 ous tube composed of movable pieces articulated together, per- 

 fectly symmetrical, wider and triangular at its upper portion, 

 which opens into the pharynx, cylindrical at its lower portion, 

 where it is continuous with the trachea. It is placed in the 

 anterior and middle portion of the neck and below the 

 hyoid bone, to which it is united by muscles and ligaments, 

 and in consequence it follows the movements of the hyoid 

 bone and the tongue, rising and falling with them. Its 

 movements are connected with deglutition, the acuteness 

 and gravity of sounds emitted, and with respiration according 

 as it is diaphragmatic or clavicular (see Respiration, p. 97). 



Five cartilages form the skeleton of the larynx; they are 



1. The cricoid cartilage (cricos, a ring); it is situated at the 

 base of the organ, and is attached to the first ring of the 

 trachea. 



2. The thyroid cartilage (thyreos, a buckler), which is com- 

 posed of two quadrilateral plates, joined together in front 



