REGISTERS OF VOICE 



505 



this instrument by Garcia (1855) physiological and pathological study of the 

 larynx entered upon an entirely new era. 



The laryngoscope is a very simple instrument. A concave mirror held before 

 the observer is provided with an aperture through which the observer looks. It 

 receives light from some artificial source, and reflects 

 it upon a plain mirror held at the proper angle in 

 the pharynx. The latter mirror serves both to illu- 

 minate the interior of the larynx and to form an 

 image of the same which can be seen by the observer. 



FIG. 203. The appearance of 

 the vocal cords while pro- 

 ducing a chest tone, after 

 Mandl. 



Fig. 202 represents a laryngoscopic picture as 

 seen in quiet breathing and Fig. 203 that seen in 

 vocalizing. 



Two different registers are distinguished : the 

 chest voice and the falsetto or head voice. The 

 former is fuller and richer i. e., richer in lower 

 overtones than the falsetto. The chest tones are 

 lower than the head tones ; although within a certain compass the same person 

 can produce identical tones with either the chest voice or the head voice. 



In the production of chest tones the vocal cords vibrate throughout their 

 entire breadth. They are also pressed inward, thus narrowing the glottis 



so that the air can only escape very 

 slowly. In the production of head 

 tones only the edges of the vocal 

 cords vibrate and the glottis is firm- 

 ly closed posteriorly, but is rather 

 widely open anteriorly. The air 

 escapes therefore more readily than 

 in the case of chest tones. For this 

 reason chest tones can be held longer 

 than head tones. 



We have the following means 

 in the larynx itself of altering the 

 pitch of the voice (Griitzner) : (1) 

 By changing the longitudinal ten- 

 sion of the vocal cords ; ( 2 ) by lim- 

 iting the vibrating length of the 

 vocal cords, which is done by ap- 

 plying the inner surfaces of the 

 arytenoid cartilages to each other 

 progressively more and more from 

 posterior to anterior ; ( 3 ) by chang- 

 ing the form of the vocalis muscle, 

 and thereby varying the width of the vocal cords; (4) by altering the air 

 pressure in the trachea. 



Higher tones within the same register therefore may be produced in two 

 general ways: (a) By increasing the tension and at the same time lengthening 

 the vocal cords; (b) by shortening the vibrating portion. Different individ- 

 uals use one or the other of these methods more or less exclusively. 



FIG. 204. Position of the vocal organs in pro- 

 ducing the sound of broad A, after Griitzner. 



