6io 



RANGE OF THE VOICE. 



band. In high falsetto notes, as many as three such nodal lines may 

 arise in succession. The formation of the nodal lines must be occasioned 

 by a partial contraction of the fibers of the internal thyro-arytenoid mus- 

 cle. At the same time the vocal bands must be stretched into the thinnest 

 possible plates by the combined action of the crico-thyroid , posterior ary- 

 tenoid, thyro-hyoid, and genio-hyoid muscles. The glottis is elliptical in 

 form, while with the chest-voice it is bounded by the straight lines of 

 the vocal bands. In the latter case more air passes out of the larynx. 



Oertel found, moreover, that with the falsetto voice the epiglottis assumes a 

 vertical position. The apices of the arytenoid cartilages are inclined somewhat 

 backward; the entire larynx appears longer in its sagittal diameter and narrower in 

 its transverse diameter; the ary-epiglottic folds are stretched tensely, with sharp 

 edges; the entrance to the ventricles of Morgagni is constricted. The vocal 

 bands are longer than in the production of the same tone with the chest-voice; 

 further, they are narrower, and the vocal processes are in contact with each other. 

 The rotation of the arytenoid cartilages necessary for this is brought about solely 

 by the lateral crico-arytenoid muscle, while the thyro-arytenoid is to be regarded 

 only as an accessory, aiding muscle. Elevation of the pitch with the falsetto voice 

 is effected exclusively by increasing the tension of the vocal bands. In addition 

 to the characteristic modification in the vibration of the vocal bands already 

 described, still another series of partly transverse and partly longitudinal partial 

 vibrations are superposed upon the former. In the case of the chest-voice a 

 narrower edge of the vocal band vibrates than in that of the falsetto voice; in 

 the production of the latter there is a feeling of less muscular exertion in the 

 larynx. The uvula is raised horizontally. In the so-called chest-register the 

 entire width of the vocal band vibrates, in the middle register only the inner 

 narrower border. In the chest-voice the overtones in the note are richest and 

 strongest, while in the falsetto voice they are less numerous and feebler. 



Pathological. By means of Oertel's laryngo-stroboscope important informa- 

 tion can be obtained concerning variations in the vibrations of the vocal bands, 

 such as unequal amplitude of vibration in the two vocal bands (laryngeal catarrh) , 

 with or without alternating vibrations; the formation of vibration-nodes in one 

 band; the absence of vibrations in one or both bands. 



In order that the voice may be produced, the following processes are 

 necessary : ( i ) The required amount of air is accumulated in the thorax ; 

 (2) the larynx and its parts are fixed in the appropriate position; (3) 

 then follows the "onset" of the voice, either the closed glottis being 

 forced open by means of an expiratory effort, or some air being per- 

 mitted to pass almost noiselessly through the glottis, and the vocal 

 bands being then thrown into vibration as the blast of air is gradually 

 increased. 



RANGE OF THE VOICE. 



The range of the human voice for the chest -register is shown in the 

 .accompanying diagram: 



256 Soprano. 1024 



T 



171 



Alto. 



684 



E F G A B c d e f g a b c / d' e x f f v' a' b/ 



128 



Tenor. 



