328 THE VOICE 



point of view, is absolutely defined by its vibration number. High 

 pitched notes have a higher rate of vibration than low pitched 

 notes. Alterations in the pitch of a note are probably brought 

 about in the larynx by altering the tension of the vocal cords, 

 by the action of the crico-thyreoid muscle the greater the 

 tension of the vibrating membrane, the higher the pitch of the 

 note produced. The part of the cords free to vibrate may be 

 varied by the approximation of the arytenoid cartilages to one 

 another. A long cord vibrates more slowly than a short one. 

 This accounts for the high pitched voices of children. 



In addition to this, it is common knowledge that when the force 

 of the blast of air is increased, .the pitch of the voice rises. There 

 is thus a tendency to sing sharp when forcing the voice, say in a 

 large badly built hall. 



In one and the same larynx, different parts or regions of the 

 scale are produced in different ways. Those notes of the scale 

 which are produced by the same means are said to be produced 

 in the same register. Thus, we produce deep notes in the chest-, 

 or thick-register, while high notes come from the high-, head-, 

 or small-register. The thin or middle register is used normally 

 by tenors and when the male voice sings falsetto. 



Laryngoscopical investigation has shown that, when producing 

 notes from the chest register, the glottis forms an elongated slit 

 and the vocal cords, stretched as tightly as possible, are vibrating 

 as thick masses over their whole extent. In taking the lowest 

 notes the posterior portion of the arytenoid cartilages are close 

 together with a wide elliptical chink between the cords. As the 

 pitch of the note rises the arytenoid cartilages are brought closer 

 together and so shortening of the vibrating portion of the cords 

 is produced. The thyreoid cartilage approximates to the cricoid 

 and the vocal cords are stretched and brought close. The 

 epiglottis rises as the pitch rises. 



When the upper limit of this register has been reached the 

 tension on the various parts is extreme and one passes with relief 

 to the middle register the normal mechanism in the female 

 (and tenors) for the production of notes between F 3 and P 4 . 

 The thyreoid cartilage returns to its normal position, the tension 

 on the cords is decreased and they vibrate at their thin mem- 

 branous edges only. As the pitch rises the thyreoid and the 

 cricoid cartilages are again pulled together by the action of the 

 crico-thyreoid muscle, and this state of tension lasts in tenors, 

 sopranos and contraltos alike from F 3 to C 4 . Higher notes than 



