488 MUSCLE-NERVE PHYSIOLOGY 



No true vocal sound is produced at the posterior part of the aperture 

 of the glottis, the part of the aperture which is formed by the space between 

 the arytenoid cartilages. For if the arytenoid cartilages be approximated in 

 such a manner that their anterior processes touch each other, but yet leave an 

 opening behind them as well as in front, no second vocal tone is produced by 

 the passage of the air through the posterior opening, but merely a rustling 

 sound. The pitch of the note produced is the same whether the posterior 

 part of the glottis be open or not. 



The Voice in Singing. The laryngeal votes may be produced in three 

 different kinds of sequence. The first is the monotonous, in which the notes 

 have nearly all the same pitch as in ordinary speaking; the variety of the sounds 

 of speech being due to articulation in the mouth. In speaking, occasional 

 syllables receive a higher intonation for the sake of accent. The second mode 

 of sequence is the successive transition from high to low notes, and vice versa, 



FIG. 349. View of the Upper Part of the Larynx as Seen by Means of the Laryngoscope 

 during the utterance of a grave note, c, Epiglottis; 5, tubercles of the cartilages of Santorini; a, 

 arytenoid cartilages; z, base of the tongue; ph, the posterior wall of the pharynx. (Czermak.) 



without intervals; such as is heard in the crying in children and in the howling 

 and whining of dogs. The third mode of sequence of the vocal sounds is the 

 musical, in which each sound has a determinate number of vibrations, and the 

 numbers of the vibrations in the successive sounds have the same relative 

 proportions that characterize the notes of the musical scale. 



The different sounds made by the musical voice are characterized by the 

 three properties of tones in general, viz., the pitch, which is dependent on the 

 rate of vibration of the vocal cords; the loudness, which depends on the force of 

 the vibration, and the quality or timber, which is dependent on the resonance of 

 the cavities of the respiratory apparatus, particularly of the mouth, pharynx, 

 and nasal cavities. 



The Vocal Range of the Voice. In different individuals this com- 

 prehends one, two, or three octaves. In singers, that is, in persons trained in 

 singing, it extends to three or more octaves. But the male and female voices 

 commence and end at different points of the musical scale. The lowest note 

 of the female voice is about an octave higher than the lowest of the male voice; 

 the highest note of the female voice about an octave higher than the'highest of 

 the male. The entire scale of the average human voice includes, from the 

 lowest male note to the highest female, about three to three and a half octaves. 



