ELEMENTS OF SPEECH 507 



tones which are favored by the shape of the cavity may be found by blowing 

 into the mouth while the organs are in the proper positions; then if these 

 tones occur as overtones in the sounds emitted by the vocal cords, they 

 are selected by the resonance of the cavity and are intensified. According 

 to Helmholtz (1863),, each vowel has one or two such tones (the pitch 

 of which is constant) which are characteristic of it whenever it is either 

 sung or spoken. Those vowels which are formed when the tongue is high in 

 the mouth, thereby dividing it into two cavities (viz., long and short A and 

 E) have two tones, and those formed when the tongue is low (viz., 00, and 

 broad A) have but one. 



B. CONSONANTS 



The consonants are much more complicated in the mode of their production 

 than the vowels, one important feature in their production consisting of 

 changes in the resonance quality of the bucco-pharyngeal space. In most of 

 the consonants the mouth and nasal cavities are separated from one another 

 by the soft palate, but in some not. But as more or less complete obstruction 

 of the air in some part of the passage is common to all, the distinguishing 

 character of the sound depends on the place and manner of the obstruction. 

 Some consonants are uttered with voice, others without. 



REFERENCES. P. Grutzner, " Physiologie der Stimme und Sprache," Leip- 

 zic, 1879 (Hermann's Handbuch der Physiologie, i, 2). //. Helmholtz, "Die 

 Lehre von den Tonempfindungen," fourth edition, Braunschweig, 1877. L. Her- 

 mann, several articles in the Archiv fur die gesamte Physiologie, vols. xlvii, 

 xlviii, liii, Iviii, Ixi, Ixxxiii, xci, 1890-1902. H. Pipping, articles in the Zeit- 

 schrift fur Biologic, vols. xxvii, xxxi, 1890, 1895. 



