VOICE AND SPEECH. 



475 



means of the laryngoscope, as well as by experiments on the 

 larynx taken from the dead body, that the sound of the human 

 voice is the result of the inferior laryngeal ligaments, or true 

 vocal cords (A, cv, Fig. 172) which bound the glottis, being 



FIG. 168. 



Outline showing the general form of the larynx, trachea, and bronchi, as seen 

 from before. %. h, the great cornu of the hyoid bone ; e, epiglottis ; t, superior, and 

 /', inferior cornu of the thyroid cartilage ; c, middle of the cricoid cartilage ; tr, the 

 trachea, showing sixteen cartilaginous rings ; ft, the right, and b', the left bronchus. 



thrown into vibration by currents of expired air impelled over 

 their edges. Thus, if a free opening exists in the trachea, the 



