MOVEMENTS OF THE GLOTTIS DURING PHONATION 439 



may be rendered regular and progressive by voluntary action, is an 

 important element in determining the timbre of the voice. 



Mechanism of the Production of the Voice. If the glottis is exam- 

 ined with the laryngoscope during ordinary respiration, the wide open- 

 ing of the chink during forced inspiration, due to the action of the 

 posterior crico-arytenoid muscles, can be observed without difficulty. This 

 action is effected by a separation of the posterior points of attach- 

 ment of the vocal chords to the arytenoid cartilages. During ordinary 

 expiration, none of the intrinsic muscles seem to act and the larynx is 

 passive, while the air is gently forced out by the elasticity of the lungs 

 and of the thoracic walls ; but so soon as a vocal effort is made, the 

 appearance of the glottis undergoes a change and it becomes modified 

 in the most varied manner with the different modifications in pitch and 

 intensity of which the voice is capable. Although sounds may be pro- 

 duced, and even words may be articulated, with the act of inspiration, 

 true and normal phonation takes place during expiration only. It 

 is evident, also, that the inferior vocal chords alone are concerned in 

 this act. 



Movements of the Glottis during Phonation. It is somewhat diffi- 

 cult to observe with the laryngoscope all the vocal phenomena, on 

 account of the epiglottis, which hides a considerable portion of the 

 vocal chords anteriorly, especially during the production of certain 

 notes ; but the patience and skill of Garcia enabled him to overcome 

 most of these difficulties, and to settle, by autolaryngoscopy, certain 

 important questions in regard to the action of the larynx in singing. 

 It is fortunate that these observations were made by one versed theo- 

 retically and practically in music and possessed of unusual control over 

 the vocal organs. 1 



Garcia, after having observed the respiratory movements of the larynx 

 as they have just been briefly described, noted that so soon as any vocal 

 effort was made, the arytenoid cartilages were approximated, so that the 

 glottis appeared as a narrow slit bounded by two chords of equal length, 

 firmly attached posteriorly as well as anteriorly. The glottis thus under- 

 goes a marked change. A nearly passive organ, opening for the pas- 

 sage of air into the lungs but inactive in expiration, has now become a 

 musical instrument, presenting a slit with borders capable of accurate 

 vibrations. 



1 Manoel Garcia, a celebrated teacher of singing in London, is regarded as the inventor of 

 the modern laryngoscope. He used this instrument for the study of the voice in his own per- 

 son and presented a memoir " Observations on the Human Voice " to the Royal Society, in 

 1855. It is only since that date that the laryngoscope has been used for medical and surgical 

 purposes. Garcia is now living and celebrated his one-hundredth birthday in London, 

 March 17, 1905. 



