168 



PHYSIOLOGY 



CHAP. 



Fricative consonants are produced by sounds of friction as 

 the expiratory current passes through the constricted oral cavity, 

 and are consequently continuous or liquid sounds like the semi- 

 vowels unlike the explosives which are instantaneous. 



The explosive consonants b, d, g\ g a , are formed with the 

 glottis open, and may be preceded and accompanied by a laryngeal 

 tone ; in p, t, c\ k, the glottis is fully closed, and the expulsion of 

 the a'ir is not accompanied by vibrations of the vocal cords. 



The labials b and p are always formed by the opening of both 

 lips In the alveolars, d, g\ t, c> the position of the tongue varies ; 



FIG. 111. Articulation of i and ai. 

 (Luciani and Baglioni.) 



FIG. 112. Articulation of ja. 

 (Luciani and Baglioni.) 



hence their sound differs more or less noticeably. The same holds 

 for the palatals g a and k (Figs. 109, 110). 



Fricative or spirant consonants are formed when the expiratory 

 blast of air is driven with a certain force through a confined 

 passage. Unlike the explosives the fricatives are preceded, not 

 by the closure, but simply by the constriction of the pharyngo- 

 buccal cavity. They may or may not be accompanied by laryngeal 

 tones, i.e. may be voiced or voiceless, w, v, the French and Italian 

 j, are pronounced with the voice ; /, the German ch and sch, and 

 French ch, without the voice; with or without, s, z and the 

 English tli. Grammarians term the sounding s and z lenes, and 

 the mute s and z fortes. But the true physiological difference is 

 that the former are accompanied by laryngeal sounds. 



The only consonant which is necessarily voiceless is li ; it may 



